To assess the relationship of tubal ligation and risk of ovarian carcinoma, we conducted a case-control, retrospective analysis of 300 ovarian carcinoma cases and 606 nonmalignant disease controls, seen between 1982 and 1988 at Roswell Park Cancer Institute, Buffalo, New York. Women who had a tubal ligation had reduced risk for the development of ovarian cancer. This relative risk was 0.52, with a 95% confidence interval 0.31 to 0.85 (p = 0.0076). Controls were matched by age. Multivariate analysis adjusted for socioeconomic level, marital status, parity, age at first pregnancy, menarche age, menopause age, irregular menses, breast-feeding duration, body habitus, and oral contraceptive use. Suggested explanations for this observation are offered.
PIP: Previous studies have revealed a significant inverse association between tubal ligation and ovarian cancer. To confirm this finding, a retrospective review was conducted of 300 ovarian carcinoma cases and 606 age-matched nonmalignant disease controls seen during 1982-88 at Roswell Park Cancer Institute (Buffalo, New York). Both cases and controls had completed a 16-page epidemiologic questionnaire on reproductive history and sociodemographic factors. Tubal ligation was reported by 27 women with ovarian cancer and 94 controls, resulting in a relative risk of 0.52 (95% confidence interval, 0.31-0.85) (p = 0.0076) for the development of ovarian cancer following tubal ligation. This risk was not altered by adjustment for socioeconomic status, marital status, nulligravidity, age at first pregnancy, age at menarche, age at menopause, irregular menses, breast feeding duration, body habitus, age, or oral contraceptive use. There was a significant trend (p = 0.0192) according to age at tubal ligation; the relative risks of developing ovarian cancer were 0.20, 0.44, 0.63, and 0.89 for women who had a tubal ligation at ages 24 years or less, 25-34 years, 35-44 years, and 45-58 years, respectively. It has been hypothesized that tubal ligation decreases ovarian cancer risk by preventing environmental carcinogens from reaching the ovaries; alternatively, tubal ligation may alter ovarian circulation and hormonal function.