The role of exogenous hormones in the epidemiology of breast, ovarian and endometrial cancer

This review focuses on the effects of oral contraceptives (OC) and estrogen replacement therapy (ERT) on the risk of breast, ovarian and endometrial cancer. The relationship between OC and cancer risk is first placed in a historical perspective. Since 1960, when OC were introduced, the hormonal composition of OC as well as the characteristics of the OC user have changed considerably. Studies conducted in the 1970s were generally reassuring, but it was not until the 1980s that studies could evaluate the effect of prolonged OC use after an extended follow-up period.