Endometrial cancer trends in England and Wales: a possible protective effect of oral contraception.

Case-control studies have shown that combined oral contraceptives (OCs) are protective against endometrial cancer. In England and Wales, OCs have been on the market for 30 years and widely used for 20 years. Trends in other known risk factors for endometrial cancer would tend to have increased its incidence in that time in women under 55 years of age. Vital statistics however show a decrease for endometrial cancer mortality (41%) and morbidity (15%) in that group. This suggests an important protective effect of OCs on this disease.