Comparison of Microwave Ablation and Transarterial Chemoembolization for Single-Nodule Hepatocellular Carcinoma Smaller Than 5cm: A Propensity Score Matching Analysis

PURPOSE: To compare overall survival (OS) and progression-free survival (PFS) between microwave ablation (MWA) and transarterial chemoembolization (TACE) for solitary hepatocellular carcinoma (HCC) smaller than 5 cm. METHODS: Patients with solitary HCC smaller than 5cm who initially underwent MWA or TACE were identified in Chinese PLA General Hospital from June 2010 to October 2015. Propensity score matching (PSM) was performed with a 1:1 matching protocol. OS and PFS were compared by using the log-rank test. After matching, subgroup analysis based on tumor size (≤3cm/3.1–5cm) was also conducted. Prognostic factors for OS and PFS were assessed with Cox proportional hazard regression model. RESULTS: A total of 202 patients (MWA, n=120; TACE, n=82) were identified. After matching, 116 patients were included (58 patients for each treatment group). MWA provided significantly better OS and PFS than TACE for both the entire cohort (OS, P<0.001; PFS, P<0.001) and the matched cohort (OS, P=0.015; PFS, P<0.001). Subgroup analysis showed that among patients with tumor of 3cm or less, the MWA group had significantly better OS (P=0.027) and PFS (P=0.008) than the TACE group. Multivariate Cox regression analysis showed TACE was associated with worse OS (hazard ratio, 2.385; 95% CI: 1.427, 3.985; P=0.001) and PFS (hazard ratio, 2.567; 95% CI: 1.820, 3.622; P<0.001). CONCLUSION: MWA outperformed TACE for solitary HCC smaller than 5cm in OS and PFS. For single tumors less than 5cm, especially those smaller ones (≤3cm), priority should be given to MWA when making treatment options between MWA and TACE.