Oral contraceptives and neoplasia: 1987 update

Abstract

This article reviews the research evidence on the relationship between oral contraceptives (OCs) and neoplasia. More recent epidemiologic studies in this area are considered to have greater validity than earlier studies, largely because of improved assessment of confounding factors. Encouraging has been the finding of a protective effect of OCs on endometrial and ovarian neoplasia: about 2000 cases of endometrial cancer and 1700 cases of ovarian cancer are averted in the US each year as a result of OC use. No consistent association, either adverse or beneficial, has emerged between OCs and breast cancer; however, high-dose combined OCs exert a protective effect on the development of benign breast disease after 2 years of use. Longterm combined OC use appears to be related to the development of benign liver lesions, but the research evidence on the association between OCs and hepatocellular carcinoma remains inconclusive. Of concern is the finding that longterm OC use is associated with an increased risk of cervical neoplasia. The mechanisms by which OCs might exert adverse effects on cervical epithelium are unclear.