Oral contraceptives and reproductive system cancer.

Extensive research during the last 20 years has shown that oral contraceptives are safe. Several recent epidemiological studies have confirmed that combined oral contraceptives (COCs) provide substantial protection against endometrial and ovarian cancer, and this protection is long-lasting and may persist for 15 or more years after termination of OC use. In many studies COCs have been associated with an increased risk of cervical abnormalities and cervical cancer, but there might be alternative explanations for these epidemiological associations (COC users can start having sexual intercourse at an earlier age, they have more sexual partners, and they rarely use barrier methods of contraception), so OCs act as a promoter for HPV-induced carcinogenesis. Finally, women who are currently using COCs or have used them in the past 10 years are at a slightly increased risk of having breast cancer during the next 10 years, although the additional cancers diagnosed tend to be localized to the breast and they are less advanced clinically than the cancers diagnosed in those who have never used COCs.