BACKGROUND: It is uncertain whether the use of an oral contraceptive increases the risk of breast cancer later in life, when the incidence of breast cancer is increased. We conducted a population-based, case-control study to determine the risk of breast cancer among former and current users of oral contraceptives. METHODS: We interviewed women who were 35 to 64 years old. A total of 4575 women with breast cancer and 4682 controls were interviewed. Conditional logistic regression was used to calculate odds ratios as estimates of the relative risk (incidence-density ratios) of breast cancer. RESULTS: The relative risk was 1.0 (95 percent confidence interval, 0.8 to 1.3) for women who were currently using oral contraceptives and 0.9 (95 percent confidence interval, 0.8 to 1.0) for those who had previously used them. The relative risk did not increase consistently with longer periods of use or with higher doses of estrogen. The results were similar among white and black women. Use of oral contraceptives by women with a family history of breast cancer was not associated with an increased risk of breast cancer, nor was the initiation of oral-contraceptive use at a young age. CONCLUSIONS: Among women from 35 to 64 years of age, current or former oral-contraceptive use was not associated with a significantly increased risk of breast cancer.
BACKGROUND: It is uncertain whether the use of an oral contraceptive increases the risk of breast cancer later in life, when the incidence of breast cancer is increased. We conducted a population-based, case-control study to determine the risk of breast cancer among former and current users of oral contraceptives. METHODS: We interviewed women who were 35 to 64 years old. A total of 4575 women with breast cancer and 4682 controls were interviewed. Conditional logistic regression was used to calculate odds ratios as estimates of the relative risk (incidence-density ratios) of breast cancer. RESULTS: The relative risk was 1.0 (95 percent confidence interval, 0.8 to 1.3) for women who were currently using oral contraceptives and 0.9 (95 percent confidence interval, 0.8 to 1.0) for those who had previously used them. The relative risk did not increase consistently with longer periods of use or with higher doses of estrogen. The results were similar among white and black women. Use of oral contraceptives by women with a family history of breast cancer was not associated with an increased risk of breast cancer, nor was the initiation of oral-contraceptive use at a young age. CONCLUSIONS: Among women from 35 to 64 years of age, current or former oral-contraceptive use was not associated with a significantly increased risk of breast cancer.
Authors: Lynn Rosenberg; Deborah A Boggs; Lauren A Wise; Lucile L Adams-Campbell; Julie R Palmer Journal: Cancer Epidemiol Biomarkers Prev Date: 2010-07-20 Impact factor: 4.254
Authors: Paula Berstad; Ralph J Coates; Leslie Bernstein; Suzanne G Folger; Kathleen E Malone; Polly A Marchbanks; Linda K Weiss; Jonathan M Liff; Jill A McDonald; Brian L Strom; Michael S Simon; Dennis Deapen; Michael F Press; Ronald T Burkman; Robert Spirtas; Giske Ursin Journal: Cancer Epidemiol Biomarkers Prev Date: 2010-05-25 Impact factor: 4.254
Authors: Winnie Yeo; Hang-Mei Lee; Amy Chan; Emily Yy Chan; Miranda Cm Chan; Keeng-Wai Chan; Sharon Ww Chan; Foon-Yiu Cheung; Polly Sy Cheung; Peter Hk Choi; Josette Sy Chor; William Wl Foo; Wing-Hong Kwan; Stephen Ck Law; Lawrence Pk Li; Janice Wh Tsang; Yuk Tung; Lorna Ls Wong; Ting-Ting Wong; Chun-Chung Yau; Tsz-Kok Yau; Benny Cy Zee Journal: World J Clin Oncol Date: 2014-12-10
Authors: L M Scott; P Durant; S Leone-Kabler; C E Wood; T C Register; A Townsend; J M Cline Journal: J Steroid Biochem Mol Biol Date: 2008-10-08 Impact factor: 4.292