Skip to main content

Main menu

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN

User menu

Search

  • Advanced search
CMAJ
  • CMAJ JOURNALS
    • CMAJ Open
    • CJS
    • JAMC
    • JPN
CMAJ

Advanced Search

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors & Reviewers
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
    • Patient engagement
  • Members & Subscribers
    • Benefits for CMA Members
    • CPD Credits for Members
    • Subscribe to CMAJ Print
    • Subscription Prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2023
  • Visit CMAJ on Facebook
  • Follow CMAJ on Twitter
  • Follow CMAJ on Pinterest
  • Follow CMAJ on Youtube
  • Follow CMAJ on Instagram
Guidelines

Recommendations on screening for breast cancer in average-risk women aged 40–74 years

The Canadian Task Force on Preventive Health Care
CMAJ November 22, 2011 183 (17) 1991-2001; DOI: https://doi.org/10.1503/cmaj.110334
  • Article
  • Figures & Tables
  • Related Content
  • Responses
  • Metrics
  • PDF
Loading
Submit a Response to This Article
Compose Response

More information about text formats

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.
References
Author Information
First or given name, e.g. 'Peter'.
Your last, or family, name, e.g. 'MacMoody'.
Your email address, e.g. higgs-boson@gmail.com
Your role and/or occupation, e.g. 'Orthopedic Surgeon'. Minimum 7 characters.
Your organization or institution (if applicable), e.g. 'Royal Free Hospital'. Minimum 12 characters.
Your organization, institution's or residential address.
Statement of Competing Interests

Vertical Tabs

Jump to comment:

  • Re:Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    Marcello Tonelli
    Posted on: 29 August 2016
  • Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    Martin J. Yaffe
    Posted on: 14 July 2016
  • Re: Printed version CMAJ:2012 May 15 Letter to the Editor: Breast Cancer Guidelines
    Wah Ting Wong
    Posted on: 28 August 2012
  • Response to Wong and Doyle
    Marcello Tonelli MD SM FRCPC
    Posted on: 28 February 2012
  • Should we not screen any more for breast cancer?
    Roger GHYS
    Posted on: 19 January 2012
  • Perspectives on the nuances in the breast screening guidelines
    Gregory P. Doyle
    Posted on: 19 January 2012
  • "Screening Mammography- What does the future hold"
    Roanne Segal
    Posted on: 05 January 2012
  • REVIEW OF NEW BREAST CANCER GUIDELINES
    IAN P GRANT-WHYTE MD
    Posted on: 12 December 2011
  • Breast Cancer Screening Recommendations Have Increased Confusion Among Patients and Physicians
    Jean M. Seely
    Posted on: 09 December 2011
  • Breast Screening Guidelines: déjà vu
    Martin Reed
    Posted on: 07 December 2011
  • Concern on the outcome of adopting the recommendations
    Wah Ting Wong
    Posted on: 07 December 2011
  • Breast Cancer- Dangerous Guidelines..
    IAN P GRANT-WHYTE MA MD(CAMBRIDGE)
    Posted on: 02 December 2011
  • Screening Recommendations: We must use science, relevant modern data and common sense in balancing benefit and harm
    Martin J Yaffe
    Posted on: 30 November 2011
  • DMIST Revisited
    Hans Krueger
    Posted on: 24 November 2011
  • Posted on: (29 August 2016)
    Page navigation anchor for Re:Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    Re:Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    • Marcello Tonelli
    • Other Contributors:

    We thank Dr. Yaffe for highlighting the paper that his group published last year in Health Reports. We will not critique the paper here except to note that it does not meet CTFPHC criteria for high quality evidence.

    The CTFPHC is presently updating its guidance on screening for breast cancer; updated recommendations are expected in 2017. We can reassure Dr. Yaffe that all relevant new evidence of sufficient quali...

    Show More

    We thank Dr. Yaffe for highlighting the paper that his group published last year in Health Reports. We will not critique the paper here except to note that it does not meet CTFPHC criteria for high quality evidence.

    The CTFPHC is presently updating its guidance on screening for breast cancer; updated recommendations are expected in 2017. We can reassure Dr. Yaffe that all relevant new evidence of sufficient quality will be considered for inclusion in the revised guideline - and that both benefits and harms will continue to inform our guidance.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (14 July 2016)
    Page navigation anchor for Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    Implications of The Canadian Preventive Health Care Recommendations on Breast Cancer Mortality
    • Martin J. Yaffe, Senior Scientist

    Randomized trials conducted in the 70s, 80s and 90s clearly demonstrated that by detecting breast cancer earlier and lessening the need to treat advanced disease, breast cancer mortality could be reduced by routine screening with mammography. These results were confirmed by the Pan Canadian Study of Mammography Screening and Mortality from Breast Cancer which showed that women who were screened in Canadian programs were m...

    Show More

    Randomized trials conducted in the 70s, 80s and 90s clearly demonstrated that by detecting breast cancer earlier and lessening the need to treat advanced disease, breast cancer mortality could be reduced by routine screening with mammography. These results were confirmed by the Pan Canadian Study of Mammography Screening and Mortality from Breast Cancer which showed that women who were screened in Canadian programs were markedly less likely to die from breast cancer than those who were not. The greatest effect was for women who began screening in their 40s where there were 44% fewer breast cancer deaths. While this was not a randomized study, it demonstrated the effectiveness of screening, because unlike the RCTs, the imaging was done within organized provincial screening programs with modern technology and current therapies.

    In 2011, The Canadian Task Force on Preventive Health Care (CTFPHC) published its recommendations on Breast Cancer Screening. Physicians and the women who are guided by them should be able to rely on such recommendations. Unfortunately, the Recommendations sent misleading and dangerous messages regarding the benefits and risks of mammography screening. These recommendations, played down the proven role of screening in reducing mortality and morbidity associated with breast cancer while portraying the limitations and/or harms of screening in a highly distorted light.

    The CTFPHC emphasized the "false positive" results of screening, implying that the harm of a woman being called back for additional non-invasive imaging to increase the confidence that cancer is not present offsets the benefit of averting a breast cancer death. Although nobody enjoys such recalls after screening, most women would declare "Nonsense!" to that implication.

    By virtue of coming from a federally-appointed task force, the recommendations of the CTFPHC have achieved a credibility which, unfortunately, is unwarranted and they have gained momentum by their endorsement by other bodies such as The Canadian College of Family Physicians, Choosing Wisely Canada and The Canadian Partnership Against Cancer. Lacking the will or resources to conduct independent critical analyses they have merely accepted the CTFPHC recommendations.

    How did the CTFPHC reach its conclusions? By relying on regurgitated opinions from the 2009 US Task Force report which promoted an anti-screening agenda, by ignoring the results of modern observational studies of effectiveness, and by refusing to consult meaningfully with scientists and physicians in Canada, who unlike the Task Force Members have expert knowledge of the benefits and limitations of screening and understand the strengths and weaknesses of the historical screening trials.

    I was concerned that the US and CTFPHC recommendations did not align with the demonstrated benefits and risks of screening as I understand them from over 35 years of research. I undertook, with colleagues at my institution, Harvard, Dartmouth and The University of Wisconsin, a study using validated computer models of breast cancer and screening to predict the effect of shifting from current Canadian practice and adopting the CTFPHC recommendations. This same type of modeling was used by the US Task Force in formulating its recommendations.

    The full details can be read in our publications in the December 2015 edition of Health Reports, but the messages are clear and are consistent with the findings of the Pan Canadian Study. Screening less (starting at 50 rather than 40 and screening biennially or triennially rather than annually) results in more breast cancer deaths and woman-years of life lost. At the same time less money will be spent on screening. There will be fewer call-back examinations and fewer needle biopsies. An example - shifting from the current regimen in several provinces of annual screening from 40-49 followed by biennial screening to 74 to dropping screening of women in their 40s would result in 414 additional breast cancer deaths in Canada each year or 12,282 woman-years of life lost. This is the equivalent of losing a widebody jet of Canadian women every year. The savings would be 196,501 fewer abnormal recalls and 22,672 fewer negative biopsies. This sounds like an awful lot of biopsies avoided until one considers that with the current regimen, for every two negative biopsies performed, an additional woman-year of life would be saved.

    For the provinces that do not accept women in their 40s into organized screening programs, our work suggests that there is currently the potential to reduce breast cancer deaths by 1.8 per 1000 women each year if those women participated in screening. This is about a 10% overall reduction in breast cancer deaths.

    In the outrageous editorial by Peter Gotzsche, accompanying the publication of the CTFPHC recommendations in CMAJ, he suggested that the best way to reduce breast cancer incidence would be to discontinue screening. Our work predicts that in Canada, this would result in as many as 1840 additional breast cancer deaths each year.

    Screening is preventive medicine in that through earlier detection it reduces the incidence of advanced disease. Screening is expensive and, indeed economics may underlie the anti-screening sentiments of some. It can be argued that there may be better ways to spend health dollars, but the suggestion that the harms of screening in any way approach the degree of benefit is not credible and is dangerous.

    Our modeling analysis is in reasonable agreement with modern studies of service screening with current technology and therapies. While screening is far from perfect, it is well past time to adopt a realistic attitude toward its proven lifesaving potential and the opportunities to reduce morbidity by treating less-advanced disease and energetically convey a more positive message to women and their physicians.

    References

    International Agency for Research on Cancer. Breast Cancer Screening IARC Handbook of Cancer Prevention Volume 15. 2016.

    Coldman A, Phillips N, Wilson C, Decker K, Chiarelli AM, Brisson J, et al. Pan-Canadian Study of Mammography Screening and Mortality from Breast Cancer. JNCI J Natl Cancer Inst. 2014; 106(11): dju261.

    Yaffe MJ, Mittmann N, Lee P, Tosteson AN, Trentham-Dietz A, Alagoz O, Stout NK. Clinical outcomes of modelling mammography screening strategies.Health Rep. 2015 Dec 16;26(12):9-15.PMID: 2667623.

    Conflict of Interest:

    My laboratory has a research collaboration on breast tomosynthesis with GE Healthcare. I hold shares in Volpara Health Technologies which produces software for quantifying breast density.

    Show Less
    Competing Interests: None declared.
  • Posted on: (28 August 2012)
    Page navigation anchor for Re: Printed version CMAJ:2012 May 15 Letter to the Editor: Breast Cancer Guidelines
    Re: Printed version CMAJ:2012 May 15 Letter to the Editor: Breast Cancer Guidelines
    • Wah Ting Wong, General Surgeon (retired)

    Important Erratum & Further appeal to the Guidelines authors, urging their consultation with the Royal College of Physicians & Surgeons of Canada

    Kindly consider inserting an erratum for a transcription error that I have just noted in the printed version of my letter which appeared in the CMAJ on May 15, 2012.

    As currently printed, the opening sentence in the second paragraph has certain omissions...

    Show More

    Important Erratum & Further appeal to the Guidelines authors, urging their consultation with the Royal College of Physicians & Surgeons of Canada

    Kindly consider inserting an erratum for a transcription error that I have just noted in the printed version of my letter which appeared in the CMAJ on May 15, 2012.

    As currently printed, the opening sentence in the second paragraph has certain omissions from my original submission (as typed within quotation marks below), making it conceptually unclear for the readers who do not refer to the online version. Kindly amended it to read:- Many women aged 40 to 49 will not opt for screening and the expectation that most women between 50-74 years "are likely to adopt screening" may not bear out, given only a weak recommendation is denoted.

    The Guidelines authors have made the following remark as part of their response: "Further, screening mammography would not be appropriate for women with the signs and symptoms described by Wong --- women in that situation should see their physicians immediately." By making such a remark, they do inadvertently endorse my original projection, in that the Task Force Guidelines bearing "weak recommendation on screening mammogram, discouragement of breast self examination and routine physician or health care provider's breast examination" will lead to the dependence on late clinical symptoms and signs for bringing the patients to see their physicians. Of course by then, diagnostic mammogram will be indicated but screening mammography inappropriate.

    The Guidelines authors have cited similar recommendations from previous national guidelines and those of other countries in support of their opinion. Such reasoning may not be infallible. We should remember that H. Pylori presumed "being Not a cause" of peptic ulcer and hormonal replacement "being the First Line therapy" for osteoporosis were incorrectly endorsed world wide for many years. Ultimately, these errors had to be corrected by the medical profession internationally. Meanwhile the Task Force Guidelines authors rightly advocate the informed choices of individual woman regarding breast cancer screening, taking self responsibility to face the clinical consequences. I submit that it is often impossible to remove all bias (1) during the discussion between the physicians and patients on making choices in clinical situations. Particularly if either or both parties are being heavily influenced by the opinion of such an august authority as the Task Force, the women's choices regarding screening for breast cancer may predictably be geared towards the predominant tone of the Task Force Guidelines. The end result will likely match my projection mentioned above.

    According to the Guidelines authors, they did not seek endorsement from the Royal College of Physicians and Surgeons of Canada nor indicate any intent to do so. It should be obvious that a uniform approach by primary care physicians and suitable consultants is deemed essential in dealing with the early diagnosis and management of such an important disorder as breast cancer. The early diagnosis of breast cancer and its clinical implication is not limited to the domain of primary physicians alone as it is just the first important step in the continuum of efficient multi-disciplinary management of the disease. By obtaining endorsement from the College of Family Physicians of Canada unilaterally, such Guidelines if generally adopted by its members in practice, may delay the diagnosis of early breast cancer. Surgeons and oncologists may have to treat many late cases in future with less satisfactory outcome. I would sincerely suggest that even now it is not too late for the Guidelines authors to seek the opinion of the RCPS of Canada for the sake of the many patients who potentially may develop breast cancer and benefit from early diagnosis and management. The general public will also expect such a co- ordinated effort from all the disciplines of physicians and surgeons who are invariably involved in the joint management of this important disorder.

    Should the Guidelines authors remain complacent with the College of Family Physicians' endorsement alone, perhaps the "Commentary" column of CMAJ may serve as a forum for an invited comment from an official representative of the Royal College of Physicians and Surgeons of Canada. The implication on women's health is too important for the issue to be left as is.

    Wah Ting Wong MB, BS; FRCS(England); FRCSC, General Surgeon (Retired), Victoria, BC.

    Reference:- 1. Daniel E. Hall, Allan V. Prochazka & Aaron S. Fink. Informed consent for clinical treatment. CMAJ 2012: 184:533-540.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (28 February 2012)
    Page navigation anchor for Response to Wong and Doyle
    Response to Wong and Doyle
    • Marcello Tonelli MD SM FRCPC

    Wah Ting Wong's letter seems to suggest that our recommendations represent a substantial departure from previous guidance. This is incorrect, since independent Canadian national guidelines did not previously recommend routine screening mammograms for average risk women aged 40-49 years; nor was routine breast self examination recommended for women of any age.

    Our guidance on mammography and breast self examinatio...

    Show More

    Wah Ting Wong's letter seems to suggest that our recommendations represent a substantial departure from previous guidance. This is incorrect, since independent Canadian national guidelines did not previously recommend routine screening mammograms for average risk women aged 40-49 years; nor was routine breast self examination recommended for women of any age.

    Our guidance on mammography and breast self examination for average risk women is consistent with national recommendations and current clinical practice from the United States, Australia and the United Kingdom. Although routine clinical breast examination has popular appeal, there is no evidence that it reduces breast cancer mortality and some evidence that it increases the risk of unnecessary breast biopsies. Although these data may be disappointing, they suggest that eliminating routine clinical breast examination would not adversely affect the health of Canadian women.

    Similarly, since the potential benefits of screening mammograms in women aged 50-74 years are accompanied by an appreciable risk of clinically relevant harms, a strong recommendation would not have been appropriate. Further, screening mammography would not be appropriate for women with the signs and symptoms described by Wah Ting Wong - such women should see their physicians immediately.

    We can reassure Wah Ting Wong that our guidelines have been formally endorsed by the College of Family Physicians of Canada. Since our guidelines are aimed at primary care practitioners, we did not seek endorsement from the Royal College of Physicians and Surgeons of Canada. We thank Gregory Doyle for the clarification regarding the recommended frequency of screening in prior CTFPHC guidance. Our document stated that the 1994 CTFPHC guidelines recommended annual mammographic screening for women aged 50-69 years, which is factually correct. We agree that it is important to clarify that subsequent CTFPHC guidance (published in 1998) amended the recommended screening frequency for this age group to 1-2 years.

    Modern approaches to breast cancer screening should encourage a careful discussion with each woman about the potential benefits as well as the potential risks and harms of screening -- and thereby support informed choices. We agree with Gregory Doyle that decision aids such as the one available from the Public Health Agency of Canada are an important tool in facilitating such discussions in conjunction with organized breast cancer screening programs.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (19 January 2012)
    Page navigation anchor for Should we not screen any more for breast cancer?
    Should we not screen any more for breast cancer?
    • Roger GHYS, Retired oncologist

    The Canadian Task Force on Preventive Health care recommends against mammographic screening before the age of 50 and, after that age, advises lenghthening the interval between mammograms from 2 to 3 years. They also recommend against MRI, clinical breast exams and breast self-examination. In essence, as far as screening for breast cancer is concerned, their advice is: DO NOTHING.

    They say that screening mammogr...

    Show More

    The Canadian Task Force on Preventive Health care recommends against mammographic screening before the age of 50 and, after that age, advises lenghthening the interval between mammograms from 2 to 3 years. They also recommend against MRI, clinical breast exams and breast self-examination. In essence, as far as screening for breast cancer is concerned, their advice is: DO NOTHING.

    They say that screening mammography leads to unnecessary biopsies - which is true - but they do not differenciate between surgical biopsies (With hospitalizations and scars sometimes larger [and uglier] than those of lumpectomies!) and trocart or needle biopsies which - with equivalent results Ref. 1,2,3 - can be done, much more cheaply , at the the Breast Clinic and leave no scar.

    In essence, they bring us back 50 years ago, when one watched until a women felt ''something'' - malignant or benign - in her breast before proceeding further. There is a general consensus that, for a woman to, more or less by accident, palpate a malignant lump in her breast, it must usually be more than 2 cm in diameter. Mammography, on the other hand, diagnoses cancers 1 cm and even sometimes 5 mm in diameter. This means going back from stage 0/I to stage II or higher lesions.

    Is that what we are aiming at ?

    References

    1. Yim JH, Barton P, Weber ar al. Mammographycally detected breast cancer. Benefits of stereotactic core versus wire localization biopsy, Ann. Surg.,1996, Jun. 223(6) 688-697, discussion 697-700.

    2. Anania G, Bazzochi M, di Loretto C et al. Percutaneous large core needle biopsy versus surgical biopsy in the diagnosis of breast lesions. Int. Surg. 1997, Jan.-Mar. 82 (1), 52-55.

    3. Morrow M, Venta L, Stinson R & Bennett C. Prospective comparison of stereotactic core biopsy and surgical excision as diagnostic procedures for breast cancer patients. Ann. Surg. 2011, Apr. 233(4), 537- 541.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (19 January 2012)
    Page navigation anchor for Perspectives on the nuances in the breast screening guidelines
    Perspectives on the nuances in the breast screening guidelines
    • Gregory P. Doyle, St. John's, Newfoundland

    Editor,

    The recent publication of the Breast Cancer Screening Guidelines generated significant interest and commentary from the media. Though the Canadian Taskforce on Preventive Healthcare (CTFPHC) has brought clarity to the issue, many physicians and women have expressed some concerns. The new guidelines are similar to the previous guidelines; however, they are more nuanced. From the perspective of organized...

    Show More

    Editor,

    The recent publication of the Breast Cancer Screening Guidelines generated significant interest and commentary from the media. Though the Canadian Taskforce on Preventive Healthcare (CTFPHC) has brought clarity to the issue, many physicians and women have expressed some concerns. The new guidelines are similar to the previous guidelines; however, they are more nuanced. From the perspective of organized population based breast cancer screening programs those nuances should be understood.

    In addition, the publication stated that the previous guidelines advised women aged 50 to 69 to have mammograms annually. In fact, the previous guidelines recommended that women aged 50 to 69 have mammograms every 1-2 years. All organized breast cancer screening programs in Canada implemented this recommendation by providing mammography every 2 years to average risk women in this age group. Average risk women aged 50-69 do not routinely receive annual mammography in Canada.

    The new CTFPHC guidelines recommend against routine screening for average risk women aged 40-49 with mammography. Explanation of these recommendations has provided some clarity for women aged 40-49, which did not exist in the previous guidelines. But the guidelines state that this recommendation is considered weak, and a weak recommendation implies some degree of choice based on individual circumstances. Therefore clinicians would need to recognize that different choices would be appropriate for individual women, and would need to provide them with assistance, to make an informed choice consistent with their values and preferences.

    For average risk women aged 50-74, the new guidelines recommend routine mammography screening every 2-3 years. This is also a weak recommendation and therefore implies some degree of individual choice.

    The new CTFPHC mammography guidelines, with their weak recommendations are very reflective of the reality of mammography screening as it is currently practiced in Canada. About 70% of women aged 50-69 have utilized mammography within a 30 month time period [1]. For women aged 40-49 in Canada, about 25% have had annual mammography (ie. most women aged 40-49 have not chosen routine mammography screening, but many women have). The nuance of the guidelines is that while the recommendations do not promote screening among women aged 40-49, they do allow for screening among this age group; with informed choice based on benefits and harms associated with screening. This is an important nuance for clinicians to note.

    In Canada the age standardized mortality rate for breast cancer has fallen by over 35% since 1986 [2]; the most significant drop occurred after 1996, which was six to eight years after the introduction of organized population based breast cancer screening programs in Canada and improved quality of mammography. The decline in breast cancer mortality is attributable to both the uptake in screening and the use of more effective adjuvant therapies [3]. The age-standardized incidence rate for breast cancer in Canada has been relatively unchanged for twenty years.

    The new guidelines aim to balance the tradeoff between the harms and benefits of screening mammography, as well as patient's values and preferences. Organized population based breast cancer screening programs in Canada recognize that there are harms and benefits of screening mammograms and have produced a decision aid for women aged 40 and older (www.publichealth.gc.ca/decisionaids) to assist women in making their choice about whether to be screened. The new Canadian guidelines also direct physicians and their patients to this tool.

    In addition, the Canadian Breast Cancer Screening Initiative is in the process of developing an online CME course related to breast cancer screening that will be available in the coming months. The CME would be another tool for family physicians to understand the nuance associated with the new CTFPHC guidelines and would enable them to assist women in decision making regarding mammography screening.

    Organized high quality population based breast cancer screening programs are an important public health initiative. Screening programs that have comprehensive quality assurance and monitor their program performances have shown to be much more effective than opportunistic screening [4, 5]. Early detection, in combination with appropriate treatment significantly lowers breast cancer mortality and improves the quality of life of breast cancer patients.

    References

    1. Doyle GP, Major D, Chu C, et al.: A review of screening mammography participation and utilization in Canada. Chronic Diseases and Injuries in Canada 31(4): 152-56, 2011.

    2. Canadian Cancer Society's Steering Committee on Cancer Statistics. Canadian Cancer Statistics 2011. Toronto, ON: Canadian Cancer Society; 2011.

    3. Berry D, Cronin K, Plevritis S et al. Effect of Screening and Adjuvant Therapy on Mortality from Breast Cancer. NEJM 2005; 353, 1784- 1792.

    4. Duffy SW, Tabár L, Chen HH, et al.: The impact of organized mammography service screening on breast carcinoma mortality in seven Swedish counties. Cancer 95 (3): 458-69, 2002.

    5. Jonsson H, Nyström L, Törnberg S, et al.: Service screening with mammography of women aged 50-69 years in Sweden: effects on mortality from breast cancer. J Med Screen 8 (3): 152-60, 2001.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (5 January 2012)
    Page navigation anchor for "Screening Mammography- What does the future hold"
    "Screening Mammography- What does the future hold"
    • Roanne Segal, Medical Oncologist
    • Other Contributors:

    We read with interest the recent recommendations on breast cancer screening from The Canadian Task Force on Preventive Health Care (1). For asymptomatic women the new recommendations are: no routine mammographic screening for women 40-49, no routine clinical or breast examination for women of any age, and an increase in the screening interval from 2 to every 3 years in women aged 50 -74 (1). These recommendations are in...

    Show More

    We read with interest the recent recommendations on breast cancer screening from The Canadian Task Force on Preventive Health Care (1). For asymptomatic women the new recommendations are: no routine mammographic screening for women 40-49, no routine clinical or breast examination for women of any age, and an increase in the screening interval from 2 to every 3 years in women aged 50 -74 (1). These recommendations are in keeping with the US Preventive Services Task Force and The National Health Service in the United Kingdom (2, 3). While acknowledging the efforts of the Task Force in addressing this important public health issue, the new recommendations raise a number of important clinical questions.

    What should we recommend for women at high risk? In Ontario annual mammography and breast MRI are recommended for women aged 30 to 69 who are considered high risk due to: having or being closely related to someone with a confirmed breast cancer associated genetic mutation, a family history that indicates a hereditary breast cancer syndrome or a 25 per cent or greater lifetime risk of breast cancer, or women who have received prior radiation therapy to the chest before 30 years of age for another cancer or condition (4, 5). Clearly the absolute number of women who fall into these risk categories is limited and does not reflect the vast majority of people who develop breast cancer.

    Given that approximately 50% of women will be diagnosed with breast cancer in ages either below or above the age range recommended by the screening guidelines (6), how do we counsel these women? There can be little doubt that increased breast "awareness" in the population has resulted in more women coming forward earlier once they have breast symptoms. Clearly it is impossible to untangle the relative contribution of breast self examination, clinical breast examination by health care providers, and screening mammography on driving and maintaining this increased awareness. Sadly patients presenting with a palpable mass have larger tumours and worse outcomes than those presenting with mammographically detected tumours. They are also less likely to have had a mammogram in the preceding 12 months (7).

    Another unanswered question is: as the population ages, will the guidelines change for women over 75 years of age? It is women in this age group that now account for 28 % of all diagnosed breast cancers (6). While the Canadian Task Force states that the "absolute reduction in mortality associated with screening is unlikely among people with a limited life expectancy", this comment may not hold true as the healthy population ages. Clearly, more research into the best ways to promote breast health and breast cancer awareness in this population is needed.

    What about new screening technologies? Current guidelines are based on studies using film mammography, a technology that is being replaced with digital mammography and breast MRI. Digital mammography has recently started to declare better results in breast cancer screening, notably in young women, premenopausal and perimenopausal women, and women with dense breasts (8). Further studies are needed with the new imaging modalities to determine how they should be used for screening and in what populations.

    Breast cancer screening is complex. A number of variables including populations screened, access to screening, modality of screening and economic feasibility all play a role in defining the best approach. Canada has played a major role in breast cancer screening and moving forward should continue to be an active participant in this important public health issue (9). We clearly need to establish "who" should be screened and with what modality (e.g. mammogram, MRI). This will require on -going research in order to establish the best evidence-based approach.

    In summary, the recent recommendations on breast cancer screening put forward by the Canadian Task Force on Preventive Health has led to some concern among women and their health care providers in terms of defining the "best screening approach" for women, particularly those who are not included in the higher risk populations. It is clear that further research is needed to define the best screening techniques for women of different risk groups. In the interim women should be encouraged to discuss any breast health concerns with their health care provider. Likewise health care providers should continue to be vigilant in investigating any breast related concerns put forth by women regardless of their age or predefined risk category.

    Dr. Roanne Segal MD FRCPC, Medical Oncologist Dr. Susan Dent MD FRCPC, Medical Oncologist The Breast Disease Site Group The Ottawa Hospital Cancer Centre

    References: 1. Dickenson J, Singh H, et al: The Canadian Task Force on Preventive Health Care, November 22, 2011 183(17), pp 1991-2001

    2. U.S. Preventive Services Task Force. Screening for Breast Cancer: U.S. Preventive Services Task Force Recommendations Statement. Ann Intern Med November 17, 2009 151(10):716-726

    3. Burstow P, Patnick J, Cooke J, Dall B, Bennett R, Raime M, Sibbering M. National Health Service Breast Screening Programme 2011 Annual Review. Published 2011 | Sheffield, England. ISBN 978 1 84463 079 0. Available: http://www.cancerscreening.nhs.uk/breastscreen/publications/2011review.html (accessed 2011 Dec. 22)

    4. Ontario Ministry of Health and Long-term care. Ontario Breast Cancer Screening Program. 2011, Ottawa, Canada. Available: http://news.ontario.ca/mohltc/en/2011/05/ontario-breast-screening-program- expansion.html

    5. Fitzpatrick-Lewis D, Hodgson N, Ciliska D, et al. Breast cancer screening. October 7, 2011. Hamilton, Ontario, Canada. Available: http://canadiantaskforce.ca/recommendations/2011_01_eng.html (accessed 2011 Oct. 17).

    6. Canadian Cancer Society /National Cancer Institute of Canada. Canadian Cancer Statistics 2010, Toronto, Canada, 2010.

    7. Mathis K, Hoskin T, Boughey J, Crownhart B, Brandt K, Vachon C, Grant C, Degnim A. Palpable Presentation of Breast Cancer Persists in the Era of Screening Mammography. Journal of the American College of Surgeons 2010; 210(3): 314-318.

    8. Pisano ED, Gatonis et al. Diagnostic performance of digital versus film mammography for breast screening N Engl J Med.2005: 353:1777- 83.

    9. Miller AB, To T, Baines CJ, Wall C. Canadian national breast screening study: 1. Breast cancer mortality after 11 to 16 years of follow -up. A randomized screening trial of mammography in women age 40s. Ann Intern Med 2002;137:305-12.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (12 December 2011)
    Page navigation anchor for REVIEW OF NEW BREAST CANCER GUIDELINES
    REVIEW OF NEW BREAST CANCER GUIDELINES
    • IAN P GRANT-WHYTE MD, RETIRED

    A Review of the Canadian Task Force on Preventive Health's Guidelines for Breast Cancer Screening.

    Dr. Ian Grant- Whyte MA.MD.(Cambridge) L.M.C.C(Canada). A.B.F.P. ret. (U.S.A.)

    Hippocratic Oath: Doctor, First do no harm.

    " If I keep this oath faithfully, may I enjoy my life and practice my art, respected by all men and in all times."

    Canadian Preventive Services Task Force has done Ca...

    Show More

    A Review of the Canadian Task Force on Preventive Health's Guidelines for Breast Cancer Screening.

    Dr. Ian Grant- Whyte MA.MD.(Cambridge) L.M.C.C(Canada). A.B.F.P. ret. (U.S.A.)

    Hippocratic Oath: Doctor, First do no harm.

    " If I keep this oath faithfully, may I enjoy my life and practice my art, respected by all men and in all times."

    Canadian Preventive Services Task Force has done Canadian Women a monumental disservice, and taken the fight against breast cancer, a quantum leap backwards.

    The task force announced that it would no longer recommend routine mammograms for women between the ages of 40 and 49. This group accounts for about one out of six breast cancers. Breast cancer is the leading cause of death in women ages 40 to 49.

    The recommendation is based on data that find that mammograms reduce the risk of death in these women, but apparently not enough to recommend that all women 40 to 49 should be screened.

    These are devastatingly, inaccurate, misleading, and are "scientifically unsupportable" (Professor Martin Yaffe, Department of Medical Biophysics and Imaging, University of Toronto: personal communication, 2011) guidelines, in that major studies in Sweden and the Netherlands were entirely ignored!

    The cornerstone in our ability to save women's lives from breast cancer, is mammography.

    Modern-day mammography and today's Radiologists, have expertise far superior to those of yesteryear. The Canadian Task Force totally underestimated this fact, and Mammography`s life saving value.

    To review these terribly flawed guidelines: Breast self-examination is passé( not according to the American Cancer Society and the Mayo Clinic)), Clinical Breast Examination(CBE) is not recommended. ( An insult to Canadian Doctors), and Mammography should be delayed until age 50, then every two or three years, thereafter. There is no abrupt change in breast cancer incidence at age 50.

    Have you any idea how breast cancers can spread (metastasize) in a 2 or 3 years?

    Have you ever visited a loved one in a hospice?

    How many lives are enough to make routine annual screening worthwhile? The test is far from perfect, but it is the best we have to offer women at this point in time. Mammography can reveal a tumor less than one centimeter in diameter. Breast Cancer often begins as a small hard painless lump.

    No Doctor or Woman can find(feel) a lump that small, when early detection and treatment can often be life-saving!

    Mammograms have detected many malignancies in women in their 40s. The lives we are talking about are not inconsequential: Wives, mothers, daughters, co-workers and friends, with many years of life ahead of them.

    This is not the time to turn back the clock! Women`s lives are at stake, and finding a tumor late, often gives a poor prognosis.

    Mammography has a proven track record, and we as Doctors, "Must Do No Harm."

    By jettisoning this life-saving tool for financial gain, we are indeed harming the patient

    Dr. Ian Grant-Whyte is a graduate of Cambridge University Medical School, U.K. Prior to his retirement, Dr. Grant-Whyte's long career in family medicine spanned many years in both Canada and the United States. As a Diplomate of the American Board of Family Practice, he taught at the Phoenix Baptist Family Practice Residency Program. "The Art of Medicine." Listen to the patient, have an Inquiring Mind, carry a high index of suspicion, and always remember a breast cancer can coexist with fibro cystic disease, an extremely common condition"

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (9 December 2011)
    Page navigation anchor for Breast Cancer Screening Recommendations Have Increased Confusion Among Patients and Physicians
    Breast Cancer Screening Recommendations Have Increased Confusion Among Patients and Physicians
    • Jean M. Seely, Head of Breast Imaging
    • Other Contributors:

    The Canadian Task Force on Preventive Health Care (CTFOPH) guidelines publication last week in the CMAJ (1) has greatly increased confusion in physicians and patients. The editorial by Dr Goetzsche (2) suggesting that screening mammography should be stopped is inflammatory and highly biased. It was unfortunate that the CMAJ included this article without offering a similar opportunity to a proponent of mammographic screening...

    Show More

    The Canadian Task Force on Preventive Health Care (CTFOPH) guidelines publication last week in the CMAJ (1) has greatly increased confusion in physicians and patients. The editorial by Dr Goetzsche (2) suggesting that screening mammography should be stopped is inflammatory and highly biased. It was unfortunate that the CMAJ included this article without offering a similar opportunity to a proponent of mammographic screening in the same CMAJ issue. For the CMAJ to publish without any discussion of the downside of this perspective is irresponsible and defies principles of the Hippocratic Oath "first do no harm".

    There is ample evidence showing the benefit of screening mammography. Even the USPSTF guidelines issued in 2009 concluded that mammographic screening significantly reduces the risk of death due to breast cancer. Here in Ontario, the Ontario Breast Screening Program in Ontario in 2009- 2010 celebrated twenty years of screening for women ages 50-69 years, and showed that 19,000 cancers were detected from 1990-2007 through this program and although the incidence of breast cancer remained stable, breast cancer mortality was reduced by 35%. Similar outcomes have been seen in many other provinces in Canada, and confirming the evidence gained from prior studies worldwide showing the benefit of breast cancer screening. There are multiple studies showing that the mortality reduction from screening mammography is far greater than would be attributable to advances in chemotherapy (3-5).

    The issue of not screening women under the age of 50 is puzzling; 18% of breast cancers are detected in women ages 40-50 and 25% are diagnosed in women less than 50 years of age (TOHCC data). Forty percent of potential years of life lost to breast cancer occur among women who died of breast cancer after being diagnosed in their 40s (6). Of the few studies designed to evaluate women 40-49 years of age, a clear benefit of screening mammography has been found (7). The risk of radiation from mammography drops significantly at 40 years of age (8); there is no explanation for starting screening at 50 years of age. 50 years is not the magical age at which all women suddenly become menopausal or develop breast cancer.

    The suggestion that breast cancer screening is ineffective has sprung largely from the Nordic Cochrane group, a small group led by Dr Goetzsche, whose career has been focused on undermining the benefits of screening mammography, as well as refuting the benefits of placebos in studies. Unaccountably, Dr Goetzsche excluded 6 of the 8 randomized controlled trials and concluded there was no significant benefit in his study of screening mammography published in the Lancet 2000 (9). In the following two years, his work, which was not a Cochrane review, was refuted by several other analyses, concluding the reverse of his findings, which is that there was a significant benefit from screening mammography (10-12). It is worth noting that in the CMAJ editorial from Dr Goetzsche, 6 of the 11 references listed are from his own work(2). In contrast, a Pubmed search on the benefits of screening mammography identifies 100s of peer- reviewed studies supporting the use of screening mammography.

    The CTFOPH guidelines were developed by a group of physicians with epidemiology and family practice backgrounds, as well as a nephrologist (13). No expert opinion from breast imaging specialists or breast oncologists was obtained. This practice would not be acceptable in any other area of medicine, e.g. guidelines on management of end-of-life care would never be approved without participation of intensivists or palliative care physicians, nor would guidelines for obstetrical practice be issued without consultation by family practitioners and obstetricians. In the US, where the US preventive Services Task Force (USPSTF) were issued in 2009 against similar objections, none of the guidelines have been adopted by any scientific group with expertise in breast disease, and the American Cancer Society (ACS), American College Radiology (ACR), National Comprehensive Cancer Network (NCCN), and American College of Obstetricians and Gynecologists (ACOG) all recommend annual screening mammography, breast exam and breast awareness starting at age 40 years. A recent study evaluating screening frequency in women in Colorado in the US following publication of the USPSTF guidelines demonstrated that women did not change frequency of screening afterwards(14). There was no change in patients' screening behavior, suggesting a lack of impact of these guidelines. In the UK, the guidelines for screening now recommend screening women aged 47 years and older, a move to screen younger women, in recognition of the value of screening in this younger cohort.

    The CTFOPH and USPTFH guidelines were thus not based on new evidence, only a reinterpretation of previous evidence that was biased in favor of reduction of screening mammography. The USPSTF members have never agreed to a public debate on the guidelines since 2009. This suggests a limitation in their knowledge to do so.

    Most importantly, patients are being told not to undergo screening between the ages of 40-49 years, not to undergo breast self-examination, and not to have clinical breast exam. In his editorial, Dr Goetzsche, a statistician, alluded that women will detect their cancers at an earlier stage because of greater sensitivity and awareness. This suggests that if these guidelines are followed, the only method of detection will be when they present with disease that cannot be missed. All evidence supports improved prognosis of breast cancer from presentation at an earlier stage (15). In North America, the rate of locally advanced breast cancer, breast cancer that is only treatable with chemotherapy, is 5%. The prognosis for LABC is uniformly poor, with median survival for LABC of 4.9 years (16). In India, a country that has made the decision not to fund screening mammography, the rate of LABC is 30-60%, even among highly educated women (17). The CTFOPH and Dr Goetzsche need only to look at India to see the outcome of their recommendations of ceasing all screening mammography. We have not achieved such successes of breast cancer mortality reduction in Canada in the past 20 years only to reverse these gains without strong new evidence to the contrary.

    The editor of the CMAJ has suggested that new research addressing this subject is needed. It would be unethical to randomize women to no screening mammography given the strong benefits shown in the prior trials, involving thousands of women. A recent study published of the results of the Swedish data demonstrated strong reduction of breast cancer mortality, which was clearly distinct from the benefits of improved medical therapy (18). However, what the guidelines propose is in essence a study of new screening regimens, unsupported by prior data, and offered without informed consent. Most women, I would suggest, would not consent to this kind of experiment. Although costs are not effectively considered in the recommendation, there are clear implications of decreasing the frequency of screening mammography that must be considered and a method of reducing costs at the front end. What should also be considered are the downstream costs: costs of treating patients with more advanced tumors with lymph node metastases, requiring more toxic and expensive chemotherapy.

    The issue of harms from screening mammography is exaggerated greatly by the CTFOPH. In daily discussion with patients about the harms from a false positive of a screening mammogram, all state emphatically that they need to know, and do not object to the extra care. Women will tolerate a little anxiety, but they won't tolerate a little cancer. We owe these patients the right of knowing what they are being subjected to. Most false positives require one or more mammographic images and/or an ultrasound to clarify an abnormality. A biopsy is recommended in a minority of patients. For example, in 1000 routinely screened patients, 900 to 920 will be reassured that they have a normal mammogram. Of the 80-100 called back for extra views, 45 to 65 of those recalled will have nothing of concern ("false positives"); 20 may be asked to return in 6 months, with the area followed having less than a 2% chance of malignancy; 15 will be recommended for biopsy, usually a needle biopsy; and 2 to 5 of women biopsied will be found to have breast cancer (18). These rates are closely monitored; a radiologist who exceeds the normal call back rate must undergo extra training to return to the norm. Similarly, rates of biopsy recommendations by radiologists are closely monitored. Nowhere else in medicine are outcomes as tightly monitored as in mammography.

    The allegation that the possibility of having a negative biopsy result should preclude doing the biopsy altogether is ludicrous. We do not stop performing a thyroid, pancreatic, lung, kidney and liver biopsy just because we know there is a chance that it will be benign. It should be no different with breast. The only difference is that we measure the rate of negative biopsies in mammography because it is one of the most tightly controlled areas in medicine.

    The responsibility of the CMAJ is to inform physicians and to clarify topics of interest in the medical field. In publishing the guidelines alongside the biased article by Peter Goetzsche, the CMAJ has lowered itself to sensational publication and has served to greatly exaggerate confusion amongst referring physicians and patients. This past 2 weeks, patients who were recalled with screening mammographic abnormalities have begun refusing mammograms for their work-ups, convinced that they will be harmed by these additional studies. A woman with a potential cancer is now unsure about how to proceed. This is not in accordance with the basic principle of "first, do no harm".

    In summary, the recommendations of the CTFOPH are not in accordance with the evidence showing clear benefits of reduction of breast cancer mortality. They were issued by individuals with no specialized knowledge of breast imaging, and will serve only to increase confusion among women who need to detect their breast cancers early. Although we may wish that breast cancer were not the leading cause of cancer in women that results in the death of thousands every year, challenging the use of screening mammography which has a proven track record of breast cancer mortality reduction by 30% will not make this wish come true. Rather, reducing screening will only serve to increase the mortality from this disease, which should be our real enemy, not each other.

    References:

    1. Care CTFoPH. Recommendations on screening for breast cancer in average-risk women aged 40-74 years. CMAJ. 2011;183(17):1991-2001. 2. Gotzsche PC. Time to stop mammography screening? CMAJ. 2011;183(17):1957-8. 3. Otto SJ, Fracheboud J, Looman CW, et al. Initiation of population-based mammography screening in Dutch municipalities and effect on breast-cancer mortality: a systematic review. Lancet. 2003;361(9367):1411-7. 4. Tabar L, Yen MF, Vitak B, Chen HH, Smith RA, Duffy SW. Mammography service screening and mortality in breast cancer patients: 20-year follow- up before and after introduction of screening. Lancet. 2003;361(9367):1405 -10. 5. Berry DA, Cronin KA, Plevritis SK, et al. Effect of screening and adjuvant therapy on mortality from breast cancer. N Engl J Med. 2005;353(17):1784-92. 6. Shapiro C, Venet W, Strax P, Venet L, al e. Periodic Screening for Breast Cancer: The Health Insurance Plan Project and its Sequelae. Baltimore, Maryland: Johns Hopkins Press, 1988. 7. Hellquist BN, Duffy SW, Abdsaleh S, et al. Effectiveness of population- based service screening with mammography for women ages 40 to 49 years: evaluation of the Swedish Mammography Screening in Young Women (SCRY) cohort. Cancer. 2011;117(4):714-22. 8. Curry TS, Dowdney JE, Murry RCJ. Christensen's Physics of Diagnostic Radiology. 4rth ed. ed. Philadelphia: Lea and Febinger, 1990. 9. Gotzsche PC, Olsen O. Is screening for breast cancer with mammography justifiable? Lancet. 2000;355(9198):129-34. 10. Freedman DA, Petitti DB, Robins JM. On the efficacy of screening for breast cancer. Int J Epidemiol. 2004;33(1):43-55. 11. van Veen WA, Knottnerus JA. [The benefit of population screening for breast cancer; an advisory report from the Health Council of the Netherlands]. Ned Tijdschr Geneeskd. 2002;146(22):1023-6. 12. Duffy SW, Tabar L, Smith RA. The mammographic screening trials: commentary on the recent work by Olsen and Gotzsche. CA Cancer J Clin. 2002;52(2):68-71. 13. http://wwwcanadiantaskforceca/members_enghtml2011. 14. Hardesty LA. The Rippling Effect of the USPSTF Screening Guidelines. In Practice, Quarterly publication of the American Roentgen Ray Society. 2011;5(4):10-1. 15. Tabar L, Dean PB. Mammography and breast cancer: the new era. Int J Gynaecol Obstet. 2003;82(3):319-26. 16. National Cancer Institute D, Surveillance Research Program, Cancer Statistics Branch. SEER Program Public Use Data Tapes 1973-1998, November 2000 Submission. In: DCCPS SRP, Cancer Statistics Branch. SEER Program Public Use Data Tapes 1973-1998, November 2000 Submission, ed.2001. 17. Rustogi A, Budrukkar A, Dinshaw K, Jalali R. Management of locally advanced breast cancer: evolution and current practice. Journal of cancer research and therapeutics. 2005;1(1):21-30. 18. Berg WA. Benefits of screening mammography. JAMA. 2010;303(2):168-9.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (7 December 2011)
    Page navigation anchor for Breast Screening Guidelines: déjà vu
    Breast Screening Guidelines: déjà vu
    • Martin Reed, Department of Diagnostic Imaging

    Anybody involved in the development of guidelines over the last few years will undoubtedly have a sensation of déjà vu when watching the reaction to the breast screening guidelines which have just been released by the Canadian Task Force on Preventative Health Care (1). The US Preventative Services Task Force released similar guidelines in 2009 and created a similar storm of controversy. The authors of the Canadian Task...

    Show More

    Anybody involved in the development of guidelines over the last few years will undoubtedly have a sensation of déjà vu when watching the reaction to the breast screening guidelines which have just been released by the Canadian Task Force on Preventative Health Care (1). The US Preventative Services Task Force released similar guidelines in 2009 and created a similar storm of controversy. The authors of the Canadian Task Force Guidelines were clearly aware of this controversy because they make reference to an article which discussed the controversy and suggested some lessons to be learned from it (2).

    Apart from the question of the appropriateness of these guidelines, the preparation and publication of this set of guidelines raises two important and related issues for the development of health care guidelines in Canada. It is now recommended and widely accepted that the development of any health care guideline should involve all stakeholders in the process, ideally by having them all represented on the guideline development committee (3,4). The authors state that "a content expert is part of the evidence review team" and they also state that "recommendations undergo internal and external peer review by experts in the field and by stakeholders and partners, such as the Canadian Breast Cancer Screening Initiative". They list the members of the "systemic review writing group", but I was unable to find any information about the affiliations, expertise or roles of the members. The majority of the members of the "guidelines writing group" are also members of the larger Task Force which ultimately reviews and approves the guideline. Information about the affiliations and expertise of the Task Force members is available on the Task Force website. The majority of the members are family physicians and clearly these are important stakeholders in a breast screening guideline because family physicians would be anticipated to be the most frequent users of such a guideline. However, there are many other stakeholders for such a guideline, including specialists in women's health, surgeons, radiologists, cancer groups and above all patients. Apart from the mention of the Canadian Breast Cancer Screening Initiative there is no other listing of which stakeholders were consulted or whether they had any representation in the guideline development process. For a guideline such as one on breast screening the involvement of patients is particularly important, and it is not clear in this report how, if at all, patients were involved or consulted.

    A meeting was recently held in Gatineau, organized by the Canadian Medical Association, the Health Council of Canada, the Centre for Effective Practice, the Canadian Agency for Drugs and Technologies in Health and the Canadian Association of Radiologists. This meeting brought together many of the organizations and individuals involved in guideline production in Canada. The goal of this meeting was to craft a national strategy for health care guideline development in Canada.

    Being aware of the potential controversy that would result from the publication of their breast screening guidelines, it is unfortunate that the Canadian Task Force did not take some steps to mitigate this controversy. This type of controversy is distressing for the people we should care most about, our patients. It does nothing to help the audience it was primarily designed for, family physicians. It is of no benefit to medical policy makers. It also casts a bad light on the whole of the medical community. One of the results to be hoped for from the meeting in Gatineau is a national strategy which will promote and facilitate increased coordination, cooperation and consultation between the various organizations which produce guidelines in Canada so that this type of controversy over important medical guidelines does not happen again.

    References

    1. The Canadian Task Force on Preventive Health Care. Recommendations on screening for breast cancer in average-risk women aged 40-74 years. CMAJ 2011;183:1991-2001

    2. Quanstrum KH, Hayward R. Lessons from the mammography wars. N Engl J Med 2010;363:1076-9.

    3. National Institute for Health and Clinical Excellence. Developing NICE clinical guidelines. www.nice.org.uk/aboutnice/howwework/developingniceclinicalguidelines/

    4. Rosenfeld RM, Shiffman RN. Clinical practice guideline development manual: a quality-driven approach for translating evidence into action. Otolaryngol Head Neck Surg. 2009;140:S1-43.

    Martin H. Reed MD FRCPC Department of Diagnostic Imaging Children's Hospital Winnipeg, Manitoba Chair, Guidelines Working Group Canadian Association of Radiologists

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (7 December 2011)
    Page navigation anchor for Concern on the outcome of adopting the recommendations
    Concern on the outcome of adopting the recommendations
    • Wah Ting Wong, Physician

    I would like to voice my comments on the important recommendations published by the Canadian Task Force on "Preventive Health Care on screening for breast cancer in average risk women aged 40-74 years". Undoubtedly the authors had spent extensive time in reviewing the literature and come up with the controversial set of recommendations. Additionally in the on-line appendix 2 of the paper, the authors conjectured that cl...

    Show More

    I would like to voice my comments on the important recommendations published by the Canadian Task Force on "Preventive Health Care on screening for breast cancer in average risk women aged 40-74 years". Undoubtedly the authors had spent extensive time in reviewing the literature and come up with the controversial set of recommendations. Additionally in the on-line appendix 2 of the paper, the authors conjectured that clinical breast examination remains appropriate when women present with, or physicians have concerns about abnormal changes. The debate on whether screening mammography simply helps to discover many insignificant cancerous foci that may be immaterial to the survival of some patients or every early cancer detected & treated is reckoned to be an additional life saved will probably be on-going. Further more, there is the valid question of whether clinical examinations &/or self- examinations of the breast are of value in early detection of breast cancers thus affording better outcome from treatment? Despite these unsettled debates, one pertinent question that a clinician should ask is:- "If the Task Force's recommendations are adopted by patients and physicians alike, how is breast cancer going to be diagnosed and brought to treatment in future?"

    The logical derivations towards answering the above question will be like these:-

    1.Since for women aged 40-49 years routine screening with mammography is not recommended, very few would self-refer for screening or discuss with their physicians and adopt screening. 2.Since the recommendation for women aged 50-69 as well as 70-74 years to undergo routine mammographic screening is only a "weak recommendation", the Task Force's expectation that most women are likely to adopt the recommendation may not bear out. Most women who are intelligent and mindful to explore the details of current authoritative recommendations, will find out the denoted "weak recommendation". This will effectively discourage them from electing to have screening. 3.Since routine clinical breast examinations with or without mammography for breast cancer detection is not recommended, it is unlikely the family physicians may keep record of the patients' breast condition to effectively compare with possible subtle future changes and to raise timely concern. 4.Since routine self-examinations of the breasts are not recommended, patients hardly have a baseline condition of their breasts upon which to build the observation of any early chances in order to raise concern and report to their doctors. 5.Logically, if the Task Forces recommendations are followed, future diagnosing cancer of the breast will heavily depend on the patients observing one or more the following obvious changes and reporting for evaluation:- A. Nipple discharges & or newly developed nipple retraction; B. Unrelenting unilateral eczema of the nipple areolar complex; C. Reddening and swelling of the breast (inflammatory carcinoma of the breast simulating infection); D. Rapid enlargement of one of the breasts; E. Appearance of a visibly prominent bulge from the breast (Any mass lesion capable of producing signs denoted in D or E will likely be >2 cm in diameter thus in more advance stages); F. Orange peel appearance or retraction of the skin overlying the breast; G. Ulceration of the skin overlying a breast lump. F. Miscellaneous symptoms such as breast pain or other symptoms suggestive of regional or systemic metastatic lesions from cancer of the breast. 6.The attending doctors will only then be consulted and investigations carried out culminating in proper diagnosis and management.

    I submit that the above scenario is a regressive way of diagnosing breast cancer in this day and age. While every effort has recently been directed towards early diagnosis and treatment of breast cancer, to follow the Task Force's Recommendations would deem to delay the diagnosis. In their attempt to provide evidence based approach to mammographic screening, clinical common sense seems to have been overlooked. Perhaps the authors may clarify their view points in regard to my humble concerns.

    This issue is too important and the implication on women's health too wide to be left to just a few concerned doctors voicing constructive suggestions. The comments from one invited writer (not reviewed by peers) do not provide sufficient critique nor adequate guidance. It would appear appropriate for the Editorial Staffs of the CMAJ to consider soliciting the official positional statements from major organizations such as the Canadian College of Family Physicians; the Royal College of Physicians and Surgeons particularly its subdivision of General Surgeons to clarify the situation. Otherwise clinicians working in the field as well as the general public may be left in disarray. Ultimately the quality of breast cancer prevention, early detection and treatment in Canada may suffer.

    Dr. Wah Ting Wong, Victoria, BC.

    FRCS (England), FRCSC

    General Surgeon (retired)

    Conflict of interest: None.

    Note on the author of this letter: MB, BS Honors (HK), FRCS (England) & FRCSC (General Surgery). Formerly Senior Medical Officer (General Surgery Government Medical Services (HK); General Surgical Consultant Veteran Hospital & Victoria General Hospital (Victoria, BC) with Special interest in quality assurance in surgical and medical practices.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (2 December 2011)
    Page navigation anchor for Breast Cancer- Dangerous Guidelines..
    Breast Cancer- Dangerous Guidelines..
    • IAN P GRANT-WHYTE MA MD(CAMBRIDGE), retired md

    BREAST CANCER - DANGEROUS GUIDELINES

    Cancer cannot tell your age, what month it is, or what country you live in. There is often no rhyme or reason as to who gets breast cancer.

    Mammograms have detected many malignancies in women in their 40`s ,and younger. The lives we are talking about are not inconsequential: Wives,mothers, daughters,co-workers, and friends, with many years of life ahead of them....

    Show More

    BREAST CANCER - DANGEROUS GUIDELINES

    Cancer cannot tell your age, what month it is, or what country you live in. There is often no rhyme or reason as to who gets breast cancer.

    Mammograms have detected many malignancies in women in their 40`s ,and younger. The lives we are talking about are not inconsequential: Wives,mothers, daughters,co-workers, and friends, with many years of life ahead of them.

    The Canadian Service Task Force has come out with new guidelines pertaining to detection of breast cancer The Task Force guidelines preclude women between the ages of 40 and 49 from routine mammography, and rationed mammography for women age 50 and over,to mammography screening every 2 to 3 years

    Mammography is the cornerstone in our ability to save women's lives from breast cancer, and breast cancer is the main cause of death in women between the ages of 40 and 49, these guidelines are absolutely unconscionable.

    If these new guidelines persist, it could result in fewer women getting screened, and a return to the days when we caught cancers only when they were big enough to feel. .

    The task force says routine mammography would reduce deaths by about 15 percent, but just not enough of them to recommend that all women get screened.

    The panel concluded that the harms associated with mammography outweigh its benefits. When experts talk about the harms of screening, they mean things such as having additional tests to better identify what seems to be an abnormality. That usually means another mammogram and, for a small percentage of women, a biopsy to rule out breast cancer. Naturally, these false alarms can cause anxiety, but the data tell us that women know about these limitations and accept them as the price to pay for finding breast cancer early.

    Studying cancer deaths among women in their 40s reveals some important trends. Death rates were dropping slightly in the 1970s, thanks to better awareness and better treatments. By the 1990, death rates began a steep decline that continues today. While some of that drop is due to improvements in treatment, conservative estimates are that about half is due to mammography. Without mammography, many women would not be candidates for breast-conserving therapy. You cannot treat a tumor until you find it, and we know that mammography has led to finding tumors when they're smaller and far more treatable.

    The task force underestimated mammography's lifesaving value. The task force restricted its analysis to a certain kind of trial. While those trials are the strongest type, their use meant the panel was limited to reviewing an older body of evidence that underestimates the benefit of modern mammography.

    We acknowledge that there are limitations to mammography's effectiveness. It is notable, however, that data show the technology used today is much better than that used in the studies in the task force review. More modern studies show that mammography is achieving far better results than those achieved in those early experimental studies that date to the mid-1960s.

    This is not the time to turn back the clock! Women`s lives are at stake, and finding a tumor late, often gives a poor prognosis. Mammography has a proven track record, and we as Doctors, "Must Do No Harm." By jettisoning this life-saving tool for financial gain, we are indeed harming the patient Yours sincerely, Ian Grant-Whyte MA. MD.(Cambridge) L.M.C.C.(Canada) A.B.F.P.ret.(USA).

    Dr. Ian Grant-Whyte is a graduate of Cambridge University Medical School, U.K. Prior to his retirement, Dr. Grant-Whyte's long career in family medicine spanned many years in both Canada and the United States. As a Diplomate of the American Board of Family Practice, he taught at the Phoenix Baptist Family Practice Residency Program. "The Art of Medicine." Listen to the patient, have an Inquiring Mind, carry a high index of suspicion, and always remember a breast cancer can coexist with fibro cystic disease, an extremely common condition"

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
  • Posted on: (30 November 2011)
    Page navigation anchor for Screening Recommendations: We must use science, relevant modern data and common sense in balancing benefit and harm
    Screening Recommendations: We must use science, relevant modern data and common sense in balancing benefit and harm
    • Martin J Yaffe, Senior Scientist/ Professor
    • Other Contributors:

    The combination of improved therapy and screening for breast cancer with mammography is responsible for most of the 30% decrease in breast cancer mortality that has occurred in Canada over the past two decades. As researchers who have each devoted decades of work toward reducing the mortality and morbidity due to breast cancer, we are disappointed in the Recommendations of The Canadian Task Force on Preventive Health Ca...

    Show More

    The combination of improved therapy and screening for breast cancer with mammography is responsible for most of the 30% decrease in breast cancer mortality that has occurred in Canada over the past two decades. As researchers who have each devoted decades of work toward reducing the mortality and morbidity due to breast cancer, we are disappointed in the Recommendations of The Canadian Task Force on Preventive Health Care.

    The review shows clear bias in under-representing the benefits derived from screening by ignoring studies in which modern imaging technology was used. A mortality reduction of 25% or greater has been demonstrated for women over the age of 40 in studies in British Columbia and the UK. Meanwhile the Task Force accepted a much lower standard of evidence in its consideration of the "harms" of mammography screening, those of false positives and overdiagnosis. It has been shown that women are willing to accept the need for further assessment after a screening examination, provided that they have been properly educated about the limitations of screening and the implications of a positive screen. Many of the cancers detected on screening would become lethal if untreated; some would not. It is poor logic to suggest as Peter Gotzsche has done in the accompanying Commentary, that we should stop screening women and just let these cancers grow. The impact on mortality and morbidity would be substantial. This begs the question - Why was this individual, who has made a career of being opposed to screening, and whose own scientific methodology in the analysis of the breast screening literature has been heavily criticized in the literature, invited by CMAJ to write this Commentary?

    Clearly there is currently some overtreatment of DCIS and even of invasive breast cancers in relation to screening, but this occurs in non- screen detected lesions as well. The challenge is to develop better techniques clinically and in the pathology lab to help guide decisions as to which cancers require aggressive treatment and which do not. Doing away with the treatment advantages that come from finding many potentially lethal cancers by screening is an example of " throwing the baby out with the bathwater" One implication of the Recommendations is that over ten years, 2000 women whose cancer could have been detected and successfully treated in their 40s could die of breast cancer.

    For women over 50, there is no evidence for moving to a 3-year screening interval. This recommendation is at odds with the US Task Force Report from which the Canadian document appears to have been copied, but poorly. If followed, this recommendation will lead to further preventable deaths.

    If followed, these recommendations will reverse the important advances that have been demonstrated in Canada in reducing deaths from breast cancer and in permitting less debilitating treatments. Research in the UK is showing that the mastectomy rate for women 40-49 is double for those whose cancers are found clinically, compared to screen-detected. The Task Force, composed of physicians who are not experts in oncology or breast cancer, chose to carry out their activities under a cloak of secrecy and to disregard input offered by researchers more knowledgable about breast cancer screening than they as well as from the Canadian Breast Cancer Screening Initiative with whom they had committed to work. There are too many flaws in the Recommendations to detail completely here. The Recommendations as developed are not only largely without merit; they are dangerous and should be rejected by physicians and their patients and NOT adopted as health care policy by government. Furthermore, just as the US Preventive Services Task Force recommendations have influenced Canadian care, the Canadian guidelines will negatively affect the care delivered in the United States U.S. and internationally. Women and their health care providers deserve recommendations on screening based on a clear, unbiased and science-based picture of the capabilities and limitations of current methods. The Task Force has failed to provide viable guidance, wasting both our time and our money.

    Martin Yaffe, PhD Senior Scientist, Imaging Research Sunnybrook Research Institute Professor, Medical Biophysics and Medical Imaging, University of Toronto Co-Director Imaging Program - Ontario Institute for Cancer Research

    Paula Gordon, MD, FRCPC, Chair - Canadian Breast Cancer Foundation - BC/Yukon Region Early Detection Working Group, 2020 Task Force, Clinical Professor of Radiology, University of British Columbia, Medical Director, Breast Program, BC's Women's Hospital

    Eileen Rakovitch MD, FRCP(C), M.Sc. Department of Radiation Oncology Scientist, clinical epidemiology - Cancer Research Program, Odette Cancer Centre Adjunct scientist, Institute for Clinical Evaluative Sciences

    Daniel B. Kopans, M.D. Professor of Radiology - Harvard Medical School Senior Radiologist - Breast Imaging Division - Massachusetts General Hospital

    Conflict of Interest:

    MJY - conduct cooperative research with GE Healthcare and receive research support, but no personal remuneration. Co-Founder, Matakina Technologies - a manufacturer of software for measurement of breast density

    Show Less
    Competing Interests: None declared.
  • Posted on: (24 November 2011)
    Page navigation anchor for DMIST Revisited
    DMIST Revisited
    • Hans Krueger, Adjunct Professor

    The authors of the Recommendations on screening for breast cancer in average-risk women aged 40-74 years (1) briefly refer to digital mammography and, citing the DMIST trial (2), note that "the overall diagnostic accuracy of digital versus film mammography as a means of screening for breast cancer is similar, but digital mammography is more sensitive and has similar specificity for women younger than 50 years of age,...

    Show More

    The authors of the Recommendations on screening for breast cancer in average-risk women aged 40-74 years (1) briefly refer to digital mammography and, citing the DMIST trial (2), note that "the overall diagnostic accuracy of digital versus film mammography as a means of screening for breast cancer is similar, but digital mammography is more sensitive and has similar specificity for women younger than 50 years of age, women with radiographically dense breasts and premenopausal or perimenopausal women."

    What is less well known is the subsequent re-analysis of the DMIST trial results published by the authors in 2008.(3)

    The results published in 2005 assessed the overall diagnostic accuracy of digital mammography (DM) compared to film screen mammography (FSM). Overall, the results suggest no difference in the diagnostic accuracy of DM over FSM (difference between the methods in the area under the receiver operating characteristic (ROC) curve, 0.03; 95 % CI, -0.02 to 0.08; P=0.18). However, DM was found to be significantly more accurate than FSM in the following situations:

    * Women under the age of 50 years (difference between the methods in the area under the ROC curve, 0.15; 95 % CI, 0.05 to 0.25; P=0.002)

    * Women with heterogeneously dense or extremely dense breasts (difference between the methods in the area under the ROC curve, 0.11; 95 % CI, 0.04 to 0.18; P=0.003)

    * Pre- and peri-menopasual women (difference between the methods in the area under the ROC curve, 0.15; 95 % CI, 0.05 to 0.24; P=0.002)

    The authors note that "there was no significant difference in the (area under the ROC curve) between digital and film mammography among women 50 years of age or older, women with fatty breasts or scattered fibroglandular densities, and post menopausal women." Actual results for these sub-groups, however, are not presented.

    In 2008, the authors of DMIST published a more detailed analysis of the various subgroups in the trial. Using a more rigorous level of significance (controlling for multiple comparisons), the re-analysis determined that only the group of women under 50 who were also premenopausal and had dense breasts showed superior performance for DM over SFM. In women over age 65 with nondense breasts, SFM performed better than DM, although this result just failed to achieve statistical significance once the more rigorous significance level was applied (area under the ROC curve for SFM=0.88 vs. DM=0.70; P = 0.0025). In his review of DMIST, Lewin sums up the various results as follows: "the trial showed a definitive advantage for digital in younger women with dense breasts, but this was counteracted by relatively poor performance in older women with fatty breasts."(4)

    (1)The Canadian Task Force on Preventive Health Care. Recommendations on screening for breast cancer in average-risk women aged 40-74 years. Canadian Medical Association Journal. 2011; 183 (17): 1991-2001.

    (2)Pisano ED, Gatsonis C, Hendrick E et al. Diagnostic performance of digital versus film mammography for breast-cancer screening. New England Journal of Medicine. 2005; 353(17): 1773-83.

    (3)Pisano ED, Hendrick RE, Yaffe MJ et al. Diagnostic accuracy of digital versus film mammography: exploratory analysis of selected population subgroups in DMIST. Radiology. 2008; 246(2): 376-83.

    (4)Lewin JM. Digital Mammography Clinical Trials: The North American Experience. In: Bick U ,Diekmann F, eds. Digital Mammography. New York: SpringerLink; 2010.

    Conflict of Interest:

    None declared

    Show Less
    Competing Interests: None declared.
PreviousNext
Back to top

In this issue

Canadian Medical Association Journal: 183 (17)
CMAJ
Vol. 183, Issue 17
22 Nov 2011
  • Table of Contents
  • Index by author

Article extras

  • Patient Algorithm
  • Algorithme pour patients
  • Risks & Benefits, Age 40-49
  • Risques et bénéfices, 40-49 ans
  • More implementation support tools >>

Article tools

Respond to this article
Print
Download PDF
Article Alerts
To sign up for email alerts or to access your current email alerts, enter your email address below:
Email Article

Thank you for your interest in spreading the word on CMAJ.

NOTE: We only request your email address so that the person you are recommending the page to knows that you wanted them to see it, and that it is not junk mail. We do not capture any email address.

Enter multiple addresses on separate lines or separate them with commas.
Recommendations on screening for breast cancer in average-risk women aged 40–74 years
(Your Name) has sent you a message from CMAJ
(Your Name) thought you would like to see the CMAJ web site.
CAPTCHA
This question is for testing whether or not you are a human visitor and to prevent automated spam submissions.
Citation Tools
Recommendations on screening for breast cancer in average-risk women aged 40–74 years
The Canadian Task Force on Preventive Health Care
CMAJ Nov 2011, 183 (17) 1991-2001; DOI: 10.1503/cmaj.110334

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
‍ Request Permissions
Share
Recommendations on screening for breast cancer in average-risk women aged 40–74 years
The Canadian Task Force on Preventive Health Care
CMAJ Nov 2011, 183 (17) 1991-2001; DOI: 10.1503/cmaj.110334
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like

Jump to section

  • Article
    • Methods
    • Recommendations
    • Considerations for implementation
    • Other guidelines
    • Gaps in knowledge
    • Conclusion
    • Acknowledgements
    • Footnotes
    • References
  • Figures & Tables
  • Related Content
  • Responses
  • Metrics
  • PDF

Related Articles

  • Time to stop mammography screening?
  • Author affiliations
  • PubMed
  • Google Scholar

Cited By...

  • The cost-effectiveness of mammography-based female breast cancer screening in Canadian populations: a systematic review
  • Physician Perspectives on Mammography Screening for Average-Risk Women: "Like a Double-Edged Sword"
  • Effect of different communication strategies about stopping cancer screening on screening intention and cancer anxiety: a randomised online trial of older adults in Australia
  • Arrogance of 'but all you need is a good index finger: A narrative ethics exploration of lack of universal funding of PSA screening in Canada
  • Revamp governance of Canadian Task Force on Preventive Health Care
  • Importance of quality in breast cancer screening practice - a natural experiment in Alberta, Canada
  • Wise guidance and its challenges: the new Canadian recommendations on breast cancer screening
  • Recommendations on screening for breast cancer in women aged 40-74 years who are not at increased risk for breast cancer
  • Screening for a new primary cancer in patients with existing metastatic cancer: a retrospective cohort study
  • Organisation de la pratique pour le depistage preventif
  • Practice organization for preventive screening
  • Screening: when things go wrong
  • Depistage : quand les choses tournent mal
  • Red-eared zebra diagnosis: Case of relapsing polychondritis
  • Cost-effectiveness of mammography from a publicly funded health care system perspective
  • Competing demands and opportunities in primary care
  • Demandes concurrentielles et possibilites en soins primaires
  • Better decision making in preventive health screening: Balancing benefits and harms
  • Prendre de meilleures decisions en matiere de depistage preventif: Equilibrer bienfaits et prejudices
  • Examining screening mammography participation among women aged 40 to 74
  • Patterns and Predictors of Screening for Breast and Cervical Cancer in Women with CKD
  • Assessing family history of chronic disease in primary care: Prevalence, documentation, and appropriate screening
  • Bilan de sante chez ladulte: Mise a jour de Soins preventifs - Fiche de controle(C)
  • Adult health checkup: Update on the Preventive Care Checklist Form(C)
  • Mise a jour sur la prevention et le depistage selon lage a lintention des medecins de soins primaires canadiens
  • CJS debate: Is mammography useful in average-risk screening for breast cancer?
  • Update on age-appropriate preventive measures and screening for Canadian primary care providers
  • Losing touch?: Refining the role of physical examination in family medicine
  • US counties with higher rates of breast cancer screening have higher rates of incidence with no concomitant decrease in breast cancer mortality suggesting overdiagnosis
  • En perte de contact?: Revaloriser le role de lexamen physique en medecine familiale
  • Small-area variation in screening for cancer, glucose and cholesterol in Ontario: a cross-sectional study
  • Screening rates for colorectal cancer in Canada: a cross-sectional study
  • Breast Cancer Risk in Young Women in the National Breast Screening Programme: Implications for Applying NICE Guidelines for Additional Screening and Chemoprevention
  • Effect of Payment Incentives on Cancer Screening in Ontario Primary Care
  • The ethics of how to manage incidental findings
  • What is the effect of screening mammography on breast cancer incidence?
  • From ABCs to GRADE: Canadian Task Force on Preventive Health Care's new rating system for clinical practice guidelines
  • Citations of scientific results and conflicts of interest: the case of mammography screening
  • Cost effectiveness of the NHS breast screening programme: life table model
  • Applying the 2011 Canadian guidelines for breast cancer screening in practice
  • Process for guideline development by the reconstituted Canadian Task Force on Preventive Health Care
  • Physicians' attitudes and behaviour toward screening mammography in women 40 to 49 years of age
  • Toward Risk-Based Breast Cancer Screening and Prevention Strategies for Survivors of Hodgkin's Lymphoma: One Step Closer?
  • Breast cancer guidelines
  • Breast cancer guidelines
  • Breast cancer guidelines
  • Breast cancer guidelines
  • Author affiliations
  • Time to stop mammography screening?
  • Google Scholar

More in this TOC Section

  • Recommendations on screening for developmental delay
  • Recommendations on screening for lung cancer
  • Recommendations on screening for colorectal cancer in primary care
Show more Guidelines

Similar Articles

Collections

  • Article Types
    • Guidelines
  • Topics
    • Cancer: breast

 

View Latest Classified Ads

Content

  • Current issue
  • Past issues
  • Collections
  • Sections
  • Blog
  • Podcasts
  • Alerts
  • RSS
  • Early releases

Information for

  • Advertisers
  • Authors
  • Reviewers
  • CMA Members
  • CPD credits
  • Media
  • Reprint requests
  • Subscribers

About

  • General Information
  • Journal staff
  • Editorial Board
  • Advisory Panels
  • Governance Council
  • Journal Oversight
  • Careers
  • Contact
  • Copyright and Permissions
  • Accessibiity
  • CMA Civility Standards
CMAJ Group

Copyright 2023, CMA Impact Inc. or its licensors. All rights reserved. ISSN 1488-2329 (e) 0820-3946 (p)

All editorial matter in CMAJ represents the opinions of the authors and not necessarily those of the Canadian Medical Association or its subsidiaries.

To receive any of these resources in an accessible format, please contact us at CMAJ Group, 500-1410 Blair Towers Place, Ottawa ON, K1J 9B9; p: 1-888-855-2555; e: cmajgroup@cmaj.ca

Powered by HighWire