Prophylactic oophorectomy in surgery for large-bowel cancer.

From 1968 to 1975, 201 women had prophylactic oophorectomy at the time of definitive large-bowel resection, while in 134 patients oophorectomy was not performed. Oophorectomy was performed more commonly in women with cancer of the rectum and rectosigmoid. More patients undergoing oophorectomy had Dukes' C primary carcinoma. Four patients undergoing synchronous oophorectomy (2.0 per cent) had ovarian involvement or metastases from large-bowel cancer. Three patients (2.2 per cent) developed subsequent ovarian disease: two cases of ovarian carcinoma and one case of ovarian metastases from primary breast cancer. No late ovarian recurrences of large-bowel cancer were seen during this study. No patient with ovarian involvement or metastases from large-bowel cancer survived five years nor was the overall survival of the group of women undergoing oophorectomy materially affected. While stage and site significantly influenced survival, oophorectomy, menopausal status, preoperative irradiation, tumor size, and degree of differentiation had no influence. The prevention of primary ovarian cancer in postmenopausal women is considered to be the main benefit of bilateral prophylactic oophorectomy. Selective recommendations for oophorectomy under other circumstances are discussed.