Depth of colorectal-wall invasion and lymph-node involvement as major outcome factors influencing surgical strategy in patients with advanced and recurrent ovarian cancer with diffuse peritoneal metastases

BACKGROUND: More information is needed on the anatomopathological outcome variables indicating the appropriate surgical strategy for the colorectal resections often needed during cytoreduction for ovarian cancer. METHODS: From a phase-II study cohort including 70 patients with primary advanced or recurrent ovarian cancer with diffuse peritoneal metastases treated from November 2000 to April 2009, we selected for this study the 52 consecutive patients who needed colorectal resection. Data collected included type of colorectal resection, peritoneal cancer index (PCI), histopathology (depth of bowel-wall invasion and lymph-node spread), cytoreduction rate and outcome. Correlations were tested between possible prognostic factors and Kaplan-Meier five-year overall and disease-free survival. A Cox multivariate regression model was used to identify independent variables associated with outcome. RESULTS: In the 52 patients, the optimal cytoreduction rate was 86.5% (CC0/1). In all patients, implants infiltrated deeply into the bowel wall, in 75% of the cases up to the muscular and mucosal layer. Lymph-node metastases were detected in 50% of the cases; mesenteric nodes were involved in 42.3%. Most patients (52%) had an uneventful postoperative course. Operative mortality was 3.8%. The five-year survival rate was 49.9% and five-year disease-free survival was 36.7%. Cox regression analysis identified as the main prognostic factors completeness of cytoreduction and depth of bowel wall invasion. CONCLUSIONS: Our findings suggest that the major independent prognostic factors in patients with advanced ovarian cancer needing colorectal resections are completeness of cytoreduction and depth of bowel wall invasion. Surgical management and pathological assessment should be aware of and deal with dual locoregional and mesenteric lymphatic spread.