A Comprehensive Meta-regression Analysis on Outcome of Anatomic Resection Versus Nonanatomic Resection for Hepatocellular Carcinoma

Abstract

It remains unclear whether hepatectomy for hepatocellular carcinoma should be performed as an anatomic resection (AR) or a nonanatomic resection (NAR). Because no randomized controlled trials are currently available on this topic, a meta-regression analysis was performed on available observational studies to control for confounding variables. A systematic review of studies published from 1990 to 2011 in the PubMed and Embase databases was performed. Patient and disease-free survival (DFS), postoperative mortality, and morbidity were considered as outcomes. Results are expressed as relative risk (RR) or weighted mean differences with 95% of confidence interval. Eighteen observational studies involving 9,036 patients were analyzed: 4,012 were in the AR group and 5,024 in the NAR group. Meta-analysis suggested that AR provided better 5-year patient survival (RR 1.14; P=0.001) and DFS than NAR (RR 1.38; P=0.001). However, patients in the NAR group were characterized by a higher prevalence of cirrhosis (RR 1.27; P=0.010), more advanced hepatic dysfunction (RR 0.90 for Child-Pugh class A; P=0.001) and smaller tumor size (weighted mean difference 0.36cm; P<0.001) compared with patients in the AR group. Meta-regression analysis showed that the different proportion of cirrhosis in the NAR group significantly affected both 5-year patient survival (RR 1.28; P=0.016) and DFS (RR 1.74; P=0.022). Tumor size only slightly affected DFS (RR 1.72; P=0.076). Postoperative mortality and morbidity were unaffected (P>0.05 in all cases). Patient survival and DFS after AR seem to be superior to NAR because the worse liver function reserve in the NAR group significantly affects prognosis.