Objective. Surgical sterilization is a common method of contraception among
U.S. women, Most surgical sterilizations are tubal ligations, but few stud
ies 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 logist
ic 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 adjustme
nt and 1.4 (0.8-2.4) after adjustment for age, parity, and oral contracepti
ve use. Age at surgery, years since surgery, or calendar years of surgery w
ere not associated with endometrial cancer, and associations did not vary a
ccording to parity or stage of disease at diagnosis.
Conclusions. Tubal sterilization is not substantially associated with endom
etrial cancer. (C) 2000 Academic Press.