Impact of the degree of liver resection on survival for patients with multiple liver metastases from colorectal cancer

Background Although the degree of hepatic resection has been found to be a key aspect of tumor stimulation, the differences in clinical outcome between a massive liver resection and a less extensive resection for multiple colorectal metastases have not been well studied. The purpose of this study was to clarify the impact of the extent of liver resection on survival outcome. Methods Clinicopathologic data were available for 85 patients who were surgically treated for four or more liver metastases. Forty-nine patients who underwent a major hepatic resection were compared with patients who underwent minor hepatic resections (n = 36). Results As the patients undergoing major resection were more likely to have multiple (p = 0.014) and large tumors (p = 0.021) compared to the minor-resection patients, their overall survival was worse (p = 0.046) and the disease-free rate tended to be poorer. By multivariate analysis of the cohorts, the only independent factor affecting survival was the number of liver tumors (<= 5 or >= 6; relative risk [RR] = 0.427; p = 0.014). When patients with six or more metastases were selected and analyzed, the overall survival of patients who had a major resection was significantly poorer than those who had minor resections (p = 0.028), although the clinical characteristics were comparable between the two groups. Conclusion Although the extent of hepatectomy was not an independent prognosticator, minor resections for multiple colorectal metastases may offer a long-term survival advantage compared to a major resection.