Repeated Cytoreduction Combined with Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Selected Patients Affected by Peritoneal Metastases: Italian PSM Oncoteam Evidence.

The reiteration of surgical cytoreduction (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in patients affected by recurrent peritoneal metastases is still questioned regarding safety and effectiveness. This study evaluates the safety, efficacy, and associated factors of iterative CRS combined with HIPEC. This multicentric retrospective study collected data from four surgical oncology centers, on iterative HIPEC. We gathered data on patient and cancer characteristics, the peritoneal cancer index (PCI), completeness of cytoreduction (CC), postoperative complications, and overall survival (OS). In the study period, 141 CRS-plus-HIPECs were performed on 65 patients. Nine patients underwent three iterative procedures, and one underwent five. No increased incidence of complications after the second or third procedure was observed. Furthermore, operative time and hospitalization stay were significantly shorter after the second than after the first procedure ( p < 0.05). Optimal cytoreduction was achieved in more than 90% of cases in each procedure, whether first, second, or third. A five-year (5 y) OS represented 100% of the cases of diffuse malignant-peritoneal-mesotheliomas, 81.39% of pseudomyxoma peritonei, 34.67% of colorectal cancer (CRC), and 52.50% of ovarian cancer. During the second CRS combined with HIPEC, we observed a lower rate of complete cytoreduction and a non-significantly better survival in cases with complete cytoreduction (5 y-OS CC-0 56.51% vs. 37.82%, p = 0.061). Concomitant hepatic-CRC-metastasis did not compromise the CRS-plus-HIPEC safety and efficacy. This multicentric experience encourages repeated CRS-plus-HIPEC, showing promising results.