Survival benefit of liver resection for hepatocellular carcinoma associated with portal vein invasion: A Japanese nationwide survey.

4067 Background: The presence of portal vein tumor thrombosis (PVTT) in patients with hepatocellular carcinoma (HCC) is regarded as indicating an advanced stage, and liver resection (LR) is not recommended. The aim of this study was to evaluate the survival benefit of LR for HCC patients with PVTT through the analysis of the data from a Japanese nationwide survey. Methods: We analyzed data for 6,474 HCC patients with PVTT registered between 2000 and 2007. Of these patients, 2,093 patients who underwent LR and 4,381 patients who received other treatments were compared. The propensity scores were calculated for 1,786 patients in the LR group and 3,758 patients in the non-LR group and we successfully matched 1,229 patients (68.8% of the LR group). Results: The median survival time (MST) in the LR group was 1.93 years longer than that in the non-LR group (2.74 years vs 0.81 years; P < 0.001) and 1.03 years longer than that in the non-LR group (2.41 years vs 1.38 years; P < 0.001) in a propensity score-matched cohort. A subgroup analysis revealed that LR provides a survival benefit regardless of the Child-Pugh grade, etiology of HCC, and tumor number. The survival benefit was not statistically significant only in patients with PVTT invading the main trunk or contralateral branch. In the LR group, the postoperative mortality rate was 1.4% (29 patients) and the multivariate analysis identified liver cirrhosis (hazard ratio [HR] 1.31), Child-Pugh class B (HR 1.69), and R2 resection (HR 1.60) as significant risk factors for the overall survival other than tumor related factors. Conclusions: As long as the PVTT is limited to the first-order branch, LR leads to a longer survival outcome than non-surgical treatment, especially in the presence of good liver function.