Interaction between synchronous bilateral prophylactic oophorectomy and adjuvant chemotherapy in female patients with locally advanced colorectal cancer

Abstract

In this study we explored the prognostic impact of synchronous bilateral prophylactic oophorectomy in female patients with primary colorectal cancer undergoing radical surgery. From 1991 to 2000, 267 female patients with stage II or stage III colorectal cancer, who had undergone curative resection, were retrospectively reviewed. In 224 patients, the ovaries were preserved. The other 43 patients underwent synchronous bilateral prophylactic oophorectomy. Univariate and multivariate analyses (Kaplan-Meier and Cox regression, respectively) were used to evaluate the effect of prophylactic oophorectomy and other clinical factors on the prognosis of patients. Both univariate and multivariate analyses showed that tumor stage and adjuvant chemotherapy were the only two significant clinical factors that affected the 5-year overall survival of patients (P < 0.01). There was no significant difference in the 5-year overall survival between patients who had, or had not, undergone prophylactic oophorectomy (75%vs 73%, P > 0.05). In the subgroup analysis by adjuvant chemotherapy, the 5-year overall survival in patients receiving adjuvant chemotherapy was similar between nonoophorectomy and oophorectomy groups. However, in patients without adjuvant chemotherapy, the oophorectomy group was shown to have a significantly better 5-year overall survival than the nonoophorectomy group (76%vs 51%, P = 0.047). Prophylactic oophorectomy may improve the overall survival of female patients with locally advanced colorectal cancer without adjuvant chemotherapy, but its survival benefit vanished in patients receiving adjuvant chemotherapy. The role of prophylactic oophorectomy may be substituted by adjuvant chemotherapy, which makes prophylactic oophorectomy unnecessary during surgery for locally advanced colorectal cancer.