Encapsulation is a significant prognostic factor for better outcome in large hepatocellular carcinoma.

Background: The aim of this study was to determine the effect of tumor encapsulation of hepatocellular carcinoma (HCC) on long-term survival.

Methods: A retrospective review of 1,240 patients who underwent hepatectomy from January 1993 to June 2005 was conducted. There were 891 patients with tumor encapsulation (EC type) and 349 patients without tumor encapsulation (NC type). Clinicopathological factors, surgical outcome, and long-term survival were analyzed.

Results: Disease-free survival (DFS) was affected by surgical margin involvement, the presence of surgical complications, vascular invasion, liver cirrhosis, tumor encapsulation, tumor size >5 cm, tumor rupture, and the presence of satellite lesions (all, P < 0.05). Overall survival (OS) was also affected by the same parameters, except for satellite lesions. When the patients were grouped by tumor size >5 or ≤5 cm, the protective effect of encapsulation was only observed when the tumor size was >5 cm [odds ratio (OR) for DFS = 0.75, P = 0.02; OR for OS = 0.68, P < 0.01].

Conclusions: Tumor encapsulation is a significant prognostic factor for HCC >5 cm.