Effect of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy on relapse pattern in primary epithelial ovarian cancer: a propensity score based case-control study

OBJECTIVE: Hyperthermic intraperitoneal chemotherapy (HIPEC) has been proposed as a treatment in ovarian cancer. A recently published RCT demonstrated that HIPEC prolongs disease-free survival (DFS) and overall survival (OS) in ovarian cancer. The aim of the study was to investigate oncologic results of cytoreductive surgery+HIPEC compared with cytoreductive surgery alone in advanced primary ovarian cancer with a particular attention to the pattern of recurrence. METHODS: This is a retrospective case control study with a propensity score (PS) matching of the patients. All the patients treated for primary advanced ovarian cancer who underwent interval surgery with or without HIPEC were collected; a PS was calculated in order to match cases to controls. RESULTS: Among 77 eligible patients 56 patients were included in the study. Preoperative patients' characteristics were homogeneous. No difference in morbidity and mortality after surgery were recorded. DFS was not different among the 2 groups (13.2 vs. 13.9 months, p=0.454) but OS was better in patients treated with HIPEC with no median reached vs. 35.5 months (p=0.048). Patients treated with cytoreductive surgery alone were more likely to have a peritoneal recurrence (43% vs. 14%). CONCLUSION: HIPEC seems to affect the relapse pattern with lesser peritoneal recurrence. This difference in relapse pattern seems to affect the OS with better results in patients treated with HIPEC. Further studies are needed to confirm these findings.