Clinical Outcomes and Prognostic Factors for R0 Resected Colorectal Cancer with Synchronous Peritoneal Metastasis: A Retrospective Study

Objectives: Peritoneal metastasis indicates a poor prognosis in patients with colorectal cancer (CRC). Studies have shown improved prognosis in patients after removal of peritoneal dissemination, and this surgery is recommended if not excessively invasive. The aim of this study was to examine clinical outcomes and prognostic factors for R0 resected CRC with synchronous peritoneal metastasis. Methods: We analyzed data retrospectively from 250 patients with stage IV CRC who underwent R0 resection at our hospital. The patients were divided into three groups according to the type of surgery: nonresected (N), palliative primary tumor resection (P), and R0 resection (R0) groups. Overall survival (OS) and recurrence-free survival (RFS) were investigated and clinicopathological parameters were analyzed for prognostic significance. Results: The 3-year OS was 57.2% in the R0 group. The R0 group had a significantly higher 3-year OS than that in the other groups (p < 0.0001). Multivariate analysis revealed that histological type, lymphatic and venous invasion, liver metastasis, R0 resection, and perioperative chemotherapy were independent prognostic factors. The 5-year RFS in the R0 group was 26.5%. Multivariate analysis revealed that the number of peritoneal metastases and surgical procedure were independent prognostic factors. Laparoscopic surgery had better 5-year RFS in the R0 group compared with that in the open surgery group (p = 0.0044). Conclusions: R0 resection of colorectal cancer with synchronous peritoneal metastasis should be considered for improving long-term survival. The laparoscopic approach for this disease is another promising method to prolong survival in patients with R0 resection.