Extreme cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in treatment of peritoneal metastasis

Objective: It was aimed to define the oncologic concept of "extremeness" in cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) to determine morbidity-mortality results and final oncologic outcomes. Material and Methods: Prospectively recorded data of 666 patients with peritoneal metastases who had undergone CRS/HIPEC between 2007 and 2020 were analyzed. Patients were divided into two groups as extreme (n= 371) and non-extreme (n= 295). Extreme CRS was defined as resection of =5 major organs or creation of =2 bowel anastomoses or peritoneal carcinomatosis index (PCI)= 15 or re-cytoreductive surgery. Results: More CC-1 or CC-2 cytoreduction (p<.001), increased mortality and morbidity (p<.001), prolonged operative time (p<.001), increased intraoperative erythrocyte suspension (p<.001), albumin (p<.001), fresh frozen plasma (FFP) (p<.001), and post-operative erythrocyte suspension (p<.001) usage were found in the extreme CRS/HIPEC group. Operative time, CC-1 or CC-2 cytoreduction, presence of ostomy, development of infection, and use of intra-operative albumin and FFP were found to be independent prognostic factors in Cox regression analysis. Three and five-year survival rates were significantly lower in the extreme CRS/HIPEC group (p<.001). Conclusion: High-volume peritoneal metastatic disease can be completely resected with extreme cytoreduction in carefully selected patients responsive to chemotherapy. Since the significant morbi-mortality related to the treatment of peritoneal metastasis is a real concern, it should be considered in experienced complex cancer centers that provides relatively better oncological outcomes compared to conventional treatments.