Treatment of Microscopic Disease with Hyperthermic Intraoperative Intraperitoneal Chemotherapy After Complete Cytoreduction Improves Disease-Free Survival in Patients with Stage IIIC/IV Ovarian Cancer

We analyze the efficacy of hyperthermic intraoperative intraperitoneal chemotherapy (HIPEC) for microscopic residual disease in patients with stage IIIC/IV ovarian cancer after a complete cytoreduction of their disease. We analyzed the data of 87 consecutive patients diagnosed with stage IIIC/IV ovarian cancer operated between December 1998 and July 2011. In every patient it was possible to achieve a complete cytoreduction of their disease. (Since January 2008, our center has incorporated the use of HIPEC in patients with peritoneal surface malignancies, including patients with peritoneal dissemination of primary ovarian cancer.) Of 87 patients, 52 were treated with HIPEC (paclitaxel 60 mg/m(2), 60 min, 42 A degrees C). After a univariate analysis, factors associated with lower disease-free interval were: performing a gastrointestinal anastomosis, operative time greater than 270 min, poorly differentiated histology, and not being treated with HIPEC. After multivariate analysis, independent prognostic factors included not being treated with HIPEC [hazard ratio (HR) 8.77, 95 % CI 2.76-14.42, p < 0.01] and the presence of poorly differentiated tumors (HR 1.98, 95 % CI 1.45-8.56, p < 0.05). Disease-free survival at 1 and 3 years was 66 and 18 %, respectively, in patients without HIPEC and 81 and 63 %, respectively, in patients treated with HIPEC (p < 0.01). HIPEC administration did not alter the results obtained for disease-free survival in patients with undifferentiated tumors. The treatment of the microscopic disease following complete cytoreduction with HIPEC in patients with advanced ovarian cancer is effective and can prolong disease-free survival. This survival benefit was not seen in undifferentiated tumors.