ArticlesEndometrial cancer and oral contraceptives: an individual participant meta-analysis of 27 276 women with endometrial cancer from 36 epidemiological studies
Introduction
Use of oral contraceptives is known to reduce the incidence of endometrial cancer.1 Because endometrial cancer is uncommon in young women but its incidence increases sharply with age, the public health effects of this inverse association depend mainly on the extent to which the reduced risk of endometrial cancer persists long after use ceases. To investigate the association between use of oral contraceptives and the subsequent risk of endometrial cancer, individual participant data from 36 epidemiological studies of endometrial cancer have been brought together and analysed centrally.
Section snippets
Identification of studies and collection of data
This collaboration was established in 2005. Since 2012, epidemiological studies were eligible for inclusion if they collected individual data about use of hormonal contraceptives and reproductive history from at least 400 women with endometrial cancer in retrospective studies, and at least 200 women in prospective studies. Before 2012, retrospective studies with fewer than 400 cases of endometrial cancer had been eligible, so some studies with fewer cases are included in this analysis. Eligible
Results
Table 1 presents the details of the 36 participating studies. The studies are listed by their design and, within each type of design, by the median year when the endometrial cancers were diagnosed in each study. Most studies were done in Europe or North America, with three from Asia, one from Australia, one from South Africa, and one multinational study. Together, the analyses included 27 276 women with endometrial cancer (cases) and 115 743 women without endometrial cancer (controls). The
Discussion
This international collaboration has brought together and re-analysed almost all of the available epidemiological evidence on the reduction in endometrial cancer incidence associated with oral contraceptive use, and includes data from 27 000 women with endometrial cancer from 36 studies. Overall, the longer women had used oral contraceptives, the greater the reduction in the risk of endometrial cancer. On average, every 5 years of oral contraceptive use was associated with a relative risk of
References (60)
- et al.
Gynecological conditions and the risk of endometrial cancer
Gynecol Oncol
(2011) - et al.
Sensitivity of transvaginal ultrasound screening for endometrial cancer in postmenopausal women: a case-control study within the UKCTOCS cohort
Lancet Oncol
(2011) - et al.
Progestin and estrogen potency of combination oral contraceptives and endometrial cancer risk
Gynecol Oncol
(2006) - et al.
Long-term use of postmenopausal estrogen and progestin hormone therapies and the risk of endometrial cancer
Am J Obstet Gynecol
(2007) Combined estrogen–progestogen contraceptives and combined estrogen–progestogen menopausal therapy
(2006)- et al.
Endometrial carcinoma risks among menopausal estrogen plus progestin and unopposed estrogen users in a cohort of postmenopausal women
Cancer Epidemiol Biomarkers Prev
(2005) - et al.
Anthropometry, physical activity, and endometrial cancer risk: results from the Netherlands Cohort Study
J Natl Cancer Inst
(2004) Oral contraceptive use and mortality during 12 years of follow-up: the Nurses' Health Study
Ann Intern Med
(1994)- et al.
A prospective cohort study of cigarette smoking and the risk of endometrial cancer
Br J Cancer
(2002) - et al.
Diabetes and endometrial cancer in the Iowa Women's Health Study
Cancer Epidemiol Biomarkers Prev
(2001)
Menstrual and reproductive factors in relation to risk of endometrial cancer in Chinese women
Cancer Causes Control
Racial/ethnic differences in endometrial cancer risk: the multiethnic cohort study
Am J Epidemiol
Endometrial cancer risk factors by 2 main histologic subtypes: the NIH-AARP Diet and Health Study
Am J Epidemiol
Reproductive risk factors and endometrial cancer: the European Prospective Investigation into Cancer and Nutrition
Int J Cancer
Low-dose aspirin in the primary prevention of cancer: the Women's Health Study: a randomized controlled trial
JAMA
Recruitment methods employed in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial
Clin Trials
A population-based cohort study on the use of hormone treatment and endometrial cancer in southern Sweden
Int J Cancer
Birth weight in relation to endometrial and breast cancer risks in Swedish women
Br J Cancer
Coffee drinking and risk of endometrial cancer—a population-based cohort study
Int J Cancer
Endometrial cancer and hormone-replacement therapy in the Million Women Study
Lancet
Combination oral contraceptive use and the risk of endometrial cancer. The Cancer and Steroid Hormone Study of the Centers for Disease Control and the National Institute of Child Health and Human Development
JAMA
Oral contraceptives and endometrial cancer: do other risk factors modify the association?
Int J Cancer
Estrogen-progestin replacement therapy and endometrial cancer
J Natl Cancer Inst
Patterns of postmenopausal progestin use with estrogen in relation to endometrial cancer (United States)
Cancer Causes Control
Use of oral contraceptives and endometrial cancer risk (Sweden)
Cancer Causes Control
Organochlorines and endometrial cancer risk
Cancer Epidemiol Biomarkers Prev
Case-control study of postmenopausal hormone replacement therapy and endometrial cancer
Am J Epidemiol
Oral contraceptive and IUD use and endometrial cancer: a population-based case-control study in Shanghai, China
Int J Cancer
Reproductive risk factors for endometrial cancer among Polish women
Br J Cancer
Hormone contraception before the first birth and endometrial cancer risk
Cancer Epidemiol Biomarkers Prev
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Collaborators listed in appendix p 3