Skip to main content

Main menu

  • Home
  • Content
    • Current issue
    • Past issues
    • Early releases
    • Collections
    • Sections
    • Blog
    • Infographics & illustrations
    • Podcasts
    • COVID-19 Articles
  • Authors
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
  • CMA Members
    • Overview for members
    • Earn CPD Credits
    • Print copies of CMAJ
  • Subscribers
    • General information
    • View prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2022
  • 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
    • Overview for authors
    • Submission guidelines
    • Submit a manuscript
    • Forms
    • Editorial process
    • Editorial policies
    • Peer review process
    • Publication fees
    • Reprint requests
    • Open access
  • CMA Members
    • Overview for members
    • Earn CPD Credits
    • Print copies of CMAJ
  • Subscribers
    • General information
    • View prices
  • Alerts
    • Email alerts
    • RSS
  • JAMC
    • À propos
    • Numéro en cours
    • Archives
    • Sections
    • Abonnement
    • Alertes
    • Trousse média 2022
  • Visit CMAJ on Facebook
  • Follow CMAJ on Twitter
  • Follow CMAJ on Pinterest
  • Follow CMAJ on Youtube
  • Follow CMAJ on Instagram
Clinical Update

Colorectal cancer screening: you can't be positive about a negative result

John Hoey and Eric Wooltorton
CMAJ October 30, 2001 165 (9) 1248;
John Hoey
CMAJ
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Eric Wooltorton
CMAJ
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • Article
  • Responses
  • Metrics
  • PDF
Loading

Lieberman DA, Weiss DG. One-time screening for colorectal cancer with combined fecal occult-blood testing and examination of the distal colon. N Engl J Med 2001;345:555-60.

Background: It has been shown in several randomized trials that annual or biannual screening of asymptomatic men and women (usually over age 50) for colorectal cancer using fecal occult-blood testing reduces subsequent rates of death from this cancer.1,2 It is also believed, although the evidence is less clear-cut, that rectal and colonic polyps precede the development of cancer by several years and that removal of the polyps reduces the incidence of colon cancer. Routine sigmoidoscopy has been proposed as an alternative to fecal occult-blood testing.1

Question: Which screening test should be used to detect asymptomatic malignant and pre-malignant lesions in the large bowel: fecal occult blood testing alone or fecal occult blood testing followed by sigmoidoscopy in those with guaiac-negative stools? (All patients with a positive result from either test would undergo full gastrointestinal tract investigation, usually beginning with colonoscopy.)

Design: This study is part of a larger study for which more than 17 000 patients were recruited from 13 Veterans Affairs medical centres in the United States. Exclusion criteria included age less than 50, symptoms of disease in the lower gastrointestinal tract, a marked change in bowel habits, lower abdominal pain that would normally require a medical examination, a history of colon disease, sigmoidoscopy within the previous 10 years and a need for special precautions in performing colonoscopy.

Of the 3196 subjects who met the enrolment criteria, 2885 collected 2 stool samples on each of 3 consecutive days for fecal occult-blood testing and underwent colonoscopy. Almost all (96.8%) were men. Of the 2885 subjects, 1791 (62.1%) had no neoplastic lesions, 788 (27.3%) had tubular adenomas less than 10 mm in diameter, 233 (8.1%) had larger tubular adenomas or villous adenomas, and the remaining 73 (2.5%) had high-grade dysplasia or cancer.

The sensitivity of the fecal occult-blood test alone in detecting advanced neoplastic lesions (larger tubular adenomas, villous adenomas, high-grade dysplasia or frank carcinoma) was 23.9%. The test was slightly more sensitive (35.6%) in detecting high-grade dysplasia or carcinoma. These results are comparable with previous findings.3,4

This study also allowed the investigators to compare the results of a surrogate sigmoidoscopy (colonoscopy to the end of the sigmoid colon) with those of a full colonoscopy. Had the examination terminated at the end of the sigmoid colon, 70.3% of the subjects with advanced neoplasia would have been identified.

When combined, the fecal occult blood test and sigmoidoscopy detected 76% of the malignant and pre-malignant lesions in the large bowel and missed 24%.

Commentary: This study shows that fecal occult-blood testing combined with endoscopic examination limited to the rectum and sigmoid colon in patients who have at least 1 positive stool sample detected 76% of all worrisome lesions. The authors offered several important caveats. The results apply almost entirely to men. Importantly, the sample was highly selective, with more than 84% of the initial recruits being excluded. Thus, it may not be representative of patients seen in office practice. As well, the “sigmoidoscopy” was done with a colonoscope — rigid sigmoidoscopy would likely be less sensitive than flexible sigmoidoscopy — and the colonoscopies were done by highly skilled physicians, a situation unlikely to be duplicated if mass screening is adopted.

Lastly, it should be remembered that serious bleeding or perforation is a complication of both sigmoidoscopy and colonoscopy and that colonoscopy requires extensive bowel preparation and some sedation, is costly and may not be widely available outside of major centres. Most men undergoing the procedure (89; in this study) have no significant lesions.

Practice implications: This is a dilemma for practitioners. The standard practice, and one recommended by the Canadian Task Force on Preventive Health Care,1 is to do an annual fecal occult blood test on men and women 50 years of age and older. However, this test will miss about 76% of pre-malignant and malignant lesions of the large bowel. Adding sigmoidoscopy to the annual exam for patients who have a negative fecal occult blood test increases sensitivity, but still 24% of serious lesions are overlooked. Should one now recommend colonoscopy for all men 50 and older? Will women, who have a lower incidence of colon cancer achieve the same benefit? We've asked these questions before.5,6,7 For the moment, individual practitioners can use existing guidelines1 but they will have to make their own decisions … as usual.

References

  1. 1.↵
    Canadian Task Force on Preventive Health Care. Colorectal cancer screening. CMAJ 2001; 165:206-8.
    OpenUrlFREE Full Text
  2. 2.↵
    Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecal-occult- blood test. Lancet 1996;348:1467-71.
    OpenUrlCrossRefPubMed
  3. 3.↵
    Allison JE, Feldman F, Tekawa IS. Hemoccult screening in detecting colorectal neoplasm: sensitivity, specificity, and predictive value: long-term follow-up in a large group practice setting. Ann Intern Med 1990;112:328-33.
    OpenUrlCrossRefPubMed
  4. 4.↵
    Ahlquist DA, Wieand HS, Moertel CG, McGill DB, Loprinzi CL, O'Connell MJ, et al. Accuracy of fecal occult blood screening for colorectal neoplasia: a prospective study using Hemoccult and HemoQuant tests. JAMA 1993; 269: 1262-7.
    OpenUrlCrossRefPubMed
  5. 5.↵
    Simon JB. Screen colonoscopy: Is it time? CMAJ 2000;163(10):1277-8.
    OpenUrlFREE Full Text
  6. 6.↵
    Winawer SJ, Zauber AG. Colorectal cancer screening: Now is the time. CMAJ 2000;163(5): 543-4.
    OpenUrlFREE Full Text
  7. 7.↵
    Marshall KG. Population-based fecal occult blood screening for colon cancer: Will the benefits outweigh the risks? CMAJ 2000;163(5): 545-6.
    OpenUrlFREE Full Text
PreviousNext
Back to top

In this issue

CMAJ
Vol. 165, Issue 9
30 Oct 2001
  • Table of Contents
  • Index by author

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.
Colorectal cancer screening: you can't be positive about a negative result
(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
Colorectal cancer screening: you can't be positive about a negative result
John Hoey, Eric Wooltorton
CMAJ Oct 2001, 165 (9) 1248;

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
‍ Request Permissions
Share
Colorectal cancer screening: you can't be positive about a negative result
John Hoey, Eric Wooltorton
CMAJ Oct 2001, 165 (9) 1248;
Digg logo Reddit logo Twitter logo Facebook logo Google logo Mendeley logo
  • Tweet Widget
  • Facebook Like

Jump to section

  • Article
    • References
  • Responses
  • Metrics
  • PDF

Related Articles

  • No related articles found.
  • PubMed
  • Google Scholar

Cited By...

  • Soins primaires - les cotes difficiles
  • Primary care -- the hard parts
  • Google Scholar

More in this TOC Section

  • Early treatment of acute hepatitis C infection may lead to cure
  • Angiotensin-II–receptor blockers and nephropathy in patients with type 2 diabetes
Show more Clinical Update

Similar Articles

 

View Latest Classified Ads

Content

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

Information for

  • Advertisers
  • Authors
  • Reviewers
  • CMA Members
  • 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 2022, 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