Safety and effectiveness of subtotal pelvic peritonectomy for patients with colorectal cancer with limited peritoneal metastasis in pelvic cavity

e15587 Background: Cytoreductive surgery with extensive visceral resection and peritonectomy has shown long-term survival benefits for colorectal cancer (CRC) patients with peritoneal metastasis. However, the extent of peritonectomy remains controversial for limited peritoneal metastasis. This study modified the selective pelvic peritonectomy (SPP) to subtotal pelvic peritonectomy (STPP) for patients with limited peritoneal metastasis in pelvic cavity, and aimed to assess the outcome of STPP. Methods: CRC patients with limited peritoneal metastases in pelvic cavity and underwent R0 resection were included from a prospectively collected database. Grade III/IV morbidity rate, disease free survival (DFS) and overall survival (OS) were analyzed. Results: A total of 51 patients were included (22 in the STPP group and 29 in the SPP group). An average of 60 minutes increased in operative time in the STPP group, but no perioperative mortality occurred. Grade III/IV complication rates did not differ between two groups. At a median follow-up of 38.1 months, the 3-year-DFS was 63.0% in the STPP group and 29.3% in the SPP group ( P = 0.006). The 3-year-OS was 82.6% and 55.6% for the STPP and SPP groups, respectively ( P = 0.033). Moreover, STPP was independently associated with improved DFS. Eight (38.1%) cases with remaining ovaries developed ovarian metastasis, of whom 6 (75%) underwent a second operation. Conclusions: Subtotal pelvic peritonectomy is associated with promising long-term outcome in CRC patients with limited peritoneal metastasis in the pelvic cavity. Prophylactic bilateral oophorectomy should be strongly considered during this procedure.