Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy in Elderly Patients: Complete Cytoreduction Is Feasible and Crucial for Improved Survival Despite High Carcinomatosis Index

Background: We aimed to study the surgical outcomes of cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) in elderly patients, and investigate whether the pursuit of complete cytoreduction implies a survival benefit despite a high peritoneal carcinomatosis index (PCI). Patients and Methods: All CRS and HIPEC procedures performed for patients with peritoneal surface malignancy (PSM) >= 65 years old between 2005-2017 were included. A control group comprising patients 60-64 years old who underwent CRS and HIPEC over the same period was also selected for comparison of characteristics and outcomes. Results: A total of 54 elderly patients and 27 control patients were included. Increasing age did not result in any difference in demographics, perioperative characteristics, or surgical outcomes. Elderly patients who achieved completeness of cytoreduction (CC) 0/1 were compared to those with CC2/3, and were found to have a higher body mass index, lower peritoneal cancer index, higher rate of inpatient mortality, and a significantly longer median survival (43 vs. 15 months; p=0.020). Cox multivariate regression identified Charlson score >= 2, the occurrence of major morbidities, colorectal and sarcoma primary tumor, and CC2/3 as significant predictors of poor survival. Conclusion: CRS and HIPEC are feasible in elderly patients without a significant effect of increasing age on the surgical outcomes. CC0/1 carries higher postoperative mortality rate, but yields a longer overall survival. Baseline comorbidities, postoperative complications, certain histologies, and CC2/3 are predictors of poor prognosis in this population. PCI is a predictor of CC, but not of survival when CC0/1 is achieved.