More Synchronous Peritoneal Disease but Longer Survival in Younger Patients with Carcinomatosis from Colorectal Cancer Undergoing Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy.

BACKGROUND: Colonoscopy to detect colorectal cancer (CRC) is recommended starting at age 50 years; however, CRC rates are increasing in the prescreening population. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) has been proven effective in select patients with peritoneal carcinomatosis (PC) from CRC, although it has not been evaluated specifically in patients < 50 years. METHODS: CRC patients aged < 50 years at diagnosis undergoing CRS/HIPEC 2007-2017 were compared with those aged ≥ 50 years. Age distribution was analyzed in patients undergoing colectomy alone versus CRS/HIPEC for CRC 1993-2013. RESULTS: A total of 98 patients underwent CRS/HIPEC, of which 44% were < 50 years. Younger patients were more likely to present with synchronous peritoneal metastases (p = 0.050). Receipt of perioperative chemotherapy was comparable (p = not significant [NS]). Charlson Comorbidity Index and ECOG score were similar (p = NS). Tumor grade was similar (p = NS). Peritoneal Carcinomatosis Index, total organs resected, and anastomoses created were comparable (p = NS). Major Clavien-Dindo morbidity and LOS were similar (p = NS). Younger patients survived longer after CRS/HIPEC (p = 0.011). Demographic data from patients undergoing colectomy (n = 225) and CRS/HIPEC (n = 98) showed that age < 50 years was increasingly common with the more aggressive procedure (9% and 44% respectively, p < 0.001). CONCLUSIONS: Younger patients with PC from CRC presented more often with peritoneal metastases at the time of diagnosis. Yet despite similar perioperative features at CRS/HIPEC, they survived longer than older patients. Patients undergoing CRS/HIPEC are overall younger than those undergoing index colectomy.