Oral contraceptives and breast cancer risk among younger women.
Several studies have suggested a link between oral contraceptive use and breast cancer in younger women, but it is possible that chance or bias, including selective screening of contraceptive users, contributed to the putative association.
Given that oral contraceptives were first marketed in the United States in the early 1960s, we conducted a population-based case-control study to examine the relationship between use of oral contraceptives and breast cancer among women in a recently assembled cohort, focusing on women younger than 45 years of age who had the opportunity for exposure throughout their entire reproductive years.
Breast cancer patients and healthy control subjects were identified, the latter group by random-digit dialing, in Atlanta.
In Seattle and New Jersey, the study was confined to women 20 through 44 years of age.
Among women younger than 45 years, oral contraceptive use for 6 months or longer was associated with an RR for breast cancer of 1.3. Risks were enhanced for breast cancers occurring prior to age 35 years, with the RR rising to 2.2 for users of 10 or more years.
The RR for breast cancer for those whose oral contraceptive use began early and continued long-term (>10 years) was even higher.
The relationship between oral contraceptives and breast cancer in young women appears to have a biologic basis rather than to be an artifact or the result of bias. [J Natl Cancer Inst 87 : 827-835,1995].
Mots-clés Pascal : Tumeur maligne, Glande mammaire, Facteur risque, Epidémiologie, Contraceptif, Voie orale, Etats Unis, Amérique du Nord, Amérique, Préménopause, Adulte, Homme, Glande mammaire pathologie, Etude cas témoin
Mots-clés Pascal anglais : Malignant tumor, Mammary gland, Risk factor, Epidemiology, Contraceptive, Oral administration, United States, North America, America, Premenopause, Adult, Human, Mammary gland diseases, Case control study
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Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 95-0452442
Code Inist : 002B20E02. Création : 01/03/1996.