Clinical impact of a macroscopically complete resection of colorectal cancer with peritoneal carcinomatosis

BackgroundSo far, few reports have focused on the clinicopathological features and patterns of recurrence after a complete resection of peritoneal carcinomatosis (PC) of colorectal origin. The purpose of the present study was to show the clinicopathological features of a macroscopically complete resected tumor and the pattern of recurrence after the curative resection of colorectal PC.MethodsIn 153 patients with colorectal PC, 31 patients who underwent a complete resection of a synchronous primary lesion of a colorectal PC between 1998 and 2007 were assessed retrospectively.ResultsClinicopathological differences were observed in the tumor location, presence of extraperitoneal metastases, extent of PC, and presence of lymph node metastases between a macroscopically complete resection and noncomplete resection patients (P = .045, P < .0001, P < .001, and P = .039, respectively). Tumor recurrence after the complete resection of colorectal PC was observed in 24 patients (77.4%). The 5-year survival rate after complete resection was 36.0%. The survival rate in the macroscopically complete resection group was higher than in the incomplete resection group (P < .001). The 5-year intra- and extraperitoneal recurrence survival rates were 63.9% and 33.8%, respectively. No significant clinicopathological factors affected intraperitoneal recurrence-free survival. Conversely, a univariate analysis using the log-rank test revealed that extended PC and presence of lymph node metastases were poor factors affecting extraperitoneal recurrence (P = .009 and P = .023, respectively). Eleven of 31 patients survived for 5 years after resection. Two of the 4 patients with liver metastases had received a hepatectomy.ConclusionAlthough the 5-year survival rate after a macroscopically complete resection for colorectal PC approached 36.0%, 77.4% of patients developed intra- and extraperitoneal recurrence. Extended PC and presence of lymph node metastases were poor factors affecting extraperitoneal recurrence.