TUBAL-LIGATION AND THE RISK OF OVARIAN-CARCINOMA

To assess the relationship of tubal ligation and risk of ovarian carci noma, we conducted a case-control, retrospective analysis of 300 ovari an carcinoma cases and 606 nonmalignant disease controls, seen between 1982 and 1988 at Roswell Park Cancer Institute, Buffalo, New York. Wo men who had a tubal ligation had reduced risk for the development of o varian cancer. This relative risk was 0.52, with a 95% confidence inte rval 0.31 to 0.85 (p = 0.0076). Controls were matched by age. Multivar iate analysis adjusted for socioeconomic level, marital status, parity , age at first pregnancy, menarche age, menopause age, irregular mense s, breast-feeding duration, body habitus, and oral contraceptive use. Suggested explanations for this observation are offered.