Impact of resection and ablation for single hypovascular hepatocellular carcinoma ≤2 cm analysed with propensity score weighting

Background and Aims: Small hypovascular hepatocellular carcinoma (HCC) ≤2 cm is biologically less aggressive than hypervascular one, however, the optimal treatment is still undetermined. The efficacy of surgical resection (SR), radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) was evaluated. Methods: The 853 (SR, 176; RFA, 491; PEI, 186) patients were enrolled who met Child-Pugh A/B, single hypovascular HCC ≤2 cm pathologically proven, available tumour differentiation and absence of macrovascular invasion and extrahepatic metastasis. Overall and recurrence-free survivals were compared in original and a propensity score weighted pseudo-population with 732 patients. Results: The median follow-up time and tumour size were 2.8 years and 1.47 cm respectively. In original population, multivariate Cox regression showed no significant difference for overall survival among three groups. In pseudo-population, Cox regression also revealed no significant difference for overall survival among them, although SR (HR, 0.56; 95% CI, 0.36-0.86) and RFA (HR, 0.75; 95% CI, 0.57-1.00) groups had significantly lower recurrence than PEI group. The overall survival rates at 3 and 5 years for the SR, RFA and PEI groups were 94%/70%, 90%/75% and 94%/73% respectively. Corresponding recurrence-free survival rates were 64%/54%, 59%/41% 48%/33% respectively. Subgroup analysis revealed no significant survival benefit of SR compared with non-SR. No treatment-related death occurred. Conclusions: For patients with single hypovascular HCC ≤2 cm, no significant difference for overall survival was first identified among 3 treatment groups. The SR or RFA could be recommended, and PEI would be alternative to RFA.