Histopathologic tumor spreading in primary ovarian cancer with modified posterior exenteration

BACKGROUND: To achieve optimal cytoreduction for advanced-stage ovarian cancer, modified posterior exenteration is the most frequently performed bowel surgery. We assessed the extents of tumor spreading in the rectosigmoid wall and pelvic side wall in modified posterior exenteration specimens during primary debulking surgery (PDS) and interval debulking surgery (IDS) following neoadjuvant chemotherapy, and compared the validity of selecting this surgical procedure in the patients undergoing PDS with that in the patients undergoing IDS. METHODS: Clinicopathological data from consecutive patients who had undergone a modified posterior exenteration for primary ovarian, tubal, and peritoneal cancer at our institution between April 2008 and March 2013 was retrospectively reviewed. RESULTS: A total of 75 patients (38 in PDS and 37 in IDS) were included in this study. Tumor involvement of the rectosigmoid was histopathologically confirmed in 65 % of the specimens. Though the extent of tumor spreading in the rectosigmoid was deeper in PDS than in IDS, the frequency of tumor involvement of the rectosigmoid in patients who had undergone modified posterior exenteration during PDS was equivalent to that in the IDS group. Lateral tumor spreading to the side wall(s) was histopathologically confirmed in 53 % of the patients in whom a pelvic side wall resection had been performed. CONCLUSIONS: During both PDS and IDS for ovarian cancer presenting with tumor involvement of the cul-de-sac, close inspection and palpation by gynecologic oncologists may enable the extent of tumor spreading in the pelvis to be estimated, enabling valid decisions as to whether an en bloc resection of the pelvic tumors together with the rectosigmoid and the pelvic side wall might or might not be appropriate.