The risk factors for long-term survival outcome in solitary hepatocellular carcinoma up to 2 cm: Propensity score matching analysis in a population cohort with a high rate of HBV infection

Abstract

Background: The American Joint Committee on Cancer staging recently classified solitary hepatocellular carcinoma (HCC) ≤ 2 cm with or without vascular invasion as stage T1a. We aimed to discuss the risk factors of these stage T1a patients.

Methods: Patients diagnosed with solitary HCC ≤2 cm from September 2008 to June 2015 were included in our study. Due to the small number of patients undergoing a non-curable approach and liver transplantation, patients undergoing liver resection (LR) and radiofrequency ablation (RFA) were included. In the comparison between LR and RFA, 1:1 propensity score matching (PSM) was used. The overall survival (OS) and disease-free survival (DFS) were predicted, and the Cox proportional hazard model was used to find the prognostic factors, described as hazard ratio (HR) and 95% confidence interval (CI).

Results: In total, 273 HCC patients were involved in our study, of whom 192 patients underwent LR and 81 patients underwent RFA. The proportion of Child-Pugh A patients was higher in the LR group (91.7%) versus the RFA group (76.5%) (P = 0.001), and the tumour size was slightly larger in the LR group, with a median size of 1.9 cm versus 1.7 cm in the RFA group (P = 0.001). No difference was found in OS between LR and RFA. However, RFA was the only risk factor for recurrence (HR 1.578, 95% CI 1.006-2.467, P = 0.047). A total of 80 pairs were compared after PSM, and there was no significant difference in OS or DFS between LR and RFA after PSM (P = 0.5434 or P = 0.1642, respectively). Child-Pugh stage B was the only risk factor for OS in the multivariate analysis after PSM (HR 2.289, 95% CI 1.089-4.812, P = 0.029).

Conclusion: RFA was comparable with LR in treating solitary HCC up to 2 cm but with a higher risk for recurrence due to the imbalanced pre-operative covariates. When the pre-operative factors were consistent, liver function was the only prognostic factor for long-term OS.

Keywords: Hepatocellular carcinoma; Liver resection; Propensity score matching; Radiofrequency ablation.