Is unexpected peritoneal carcinomatosis still a contraindication for resection of colorectal liver metastases? Combined resection of colorectal liver metastases with peritoneal deposits discovered intra-operatively.

AIMS: The discovery of unexpected peritoneal carcinomatosis (PC) at the time of hepatectomy for colorectal liver metastases (CLM) is usually considered a contraindication for continuing resection. The first aim of this study was to assess the long-term outcome of patients operated for CLM, and who presented unexpected PC during laparotomy. The second aim was to identify preoperative predictors of PC. METHODS: All patients at a single center between 1985 and 2010 who had unexpected PC, discovered during planed resection of CLM, and negative preoperative imaging for PC were selected. Clinicopathological data were retrospectively analyzed to assess survival outcomes and to identify predictors of unexpected PC. RESULTS: Out of the 1340 operated patients for CLM, 42 (3%) had unexpected PC. Only patients (n = 30; 71%) who had PC limited to two abdominal regions (Median peritoneal cancer index (PCI): 2 (1-6)) were resected. Twelve patients were not resected due to the extent of peritoneal disease. The overall survival of the 30 patients resected for CLM who had limited PC was 18% at 5 years (median: 42 months). On multivariate analysis, a previous history of PC, a pT4 stage and bilobar CLM were independent predictors of unexpected PC. CONCLUSION: Unexpected PC should not be a contraindication for resection provided that the PCI is low and complete resection of all peritoneal and hepatic lesions can be achieved. Previous history of PC, a pT4 primary tumor and bilobar CLM are associated with increased risk of unexpected PC.