Tubal sterilization and risk of cancer of the endometrium.

Objective: Surgical sterilization is a common method of contraception among U.S. women. Most surgical sterilizations are tubal ligations, but few studies have investigated their potential impact on endometrial cancer risk.

Methods: A case-control study included 405 women diagnosed with endometrial cancer at 5 U.S. medical centers between 1987 and 1990 and 297 age-, race-, and location-matched controls who were identified by random-digit-dialing. Questionnaires ascertained information on tubal sterilization, and logistic regression models generated odds ratios (ORs) to estimate relative risk.

Results: The OR and 95% confidence interval for tubal sterilization, which was reported by 47 cases and 40 controls, was 0.9 (0.6-1.4) before adjustment and 1. 4 (0.8-2.4) after adjustment for age, parity, and oral contraceptive use. Age at surgery, years since surgery, or calendar years of surgery were not associated with endometrial cancer, and associations did not vary according to parity or stage of disease at diagnosis.

Conclusions: Tubal sterilization is not substantially associated with endometrial cancer.