Long-Term Survival After CRS-HIPEC for colorectal Cancer Peritoneal Metastases

BACKGROUND: Most patients with colorectal cancer (CRC) and peritoneal metastases (PM) face a dismal prognosis. Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) is a curative-intent treatment for patients with limited disease. This study assessed long-term survival and recurrence patterns. METHODS: A consecutive cohort of patients with CRC-PM treated with CRS-HIPEC. Patients with complete macroscopic cytoreduction were eligible. Main outcomes were overall survival (OS), disease-free survival (DFS), peritoneal recurrence-free survival (PRFS) and recurrence patterns. RESULTS: In total, 440 patients were evaluated over a median follow-up of 35.2 months (IQR 25.3-68.7). Induction systemic therapy was administered to 43.1% of patients. Median DFS was 9.7 months (95% CI 8.3-11.1), and median OS was 50.2 months (95% CI 44.3-56.2). Independent prognostic factors for decreased OS were Peritoneal Cancer Index (PCI) > 10, positive lymph node status (N-stage), ASA score > 2, and right-sided primary tumors. During follow-up, 71.4% of patients developed recurrent disease in the peritoneum (54.8%), lungs (22.9%), and liver (19.1%). Independent prognostic factors for decreased PRFS were lymph node metastases and higher PCI scores. Neither induction therapy nor HIPEC regimen was correlated with PRFS. Early metachronous presentation of peritoneal metastasis, also emerged as a significant adverse factor for OS, DFS and PRFS. CONCLUSIONS: Patients undergoing complete CRS-HIPEC achieved a favorable median OS exceeding 50 months, with approximately 30% of individuals exhibiting long-term survival indicative of cure. However, early recurrence remains a major problem and is in need for further research to improve CRS-HIPEC regimens.