Contraceptive surgery and breast tumors in mice

The effect of contraceptive surgical manipulations on mammary gland changes was investigated in mice models. Total hysterectomy with bilateral adnexectomy, bilateral tubal ligation, unilateral tubal ligation and moderate uterine compression were performed in various subgroups of 500 mice. Mammary gland tumors (adenomas, adenocarcinomas, squamous cell carcinomas) were observed in an average of 50% (between 20 and 66%) of the operated animals about 6 months after surgery, while the controls remained free of tumors. Surgical interference with the reproductive capacity seems to have an effect on the mammary glands, inducing neoplastic changes. The relationship of our results to the influence of contraceptive procedures on the appearance of mammary gland tumors in women is discussed.