Small Single-Nodule Hepatocellular Carcinoma: Comparison of Transarterial Chemoembolization, Radiofrequency Ablation, and Hepatic Resection by Using Inverse Probability Weighting

Purpose: To compare the effectiveness of transarterial chemoembolization (TACE), radiofrequency ablation (RFA), and hepatic resection (HR) in patients with small single-nodule hepatocellular carcinoma by using inverse probability weighting to control selection bias. Materials and Methods: This retrospective cohort study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The study included 197 consecutive patients (146 men and 51 women; mean age +/- standard deviation, 57.4 years +/- 9.7) with single-nodule hepatocellular carcinomas measuring 3 cm or smaller and no vascular invasion who were treated initially with HR (n = 52), RFA (n = 79), or TACE (n = 66) from January 2005 to December 2006 at a single tertiary hospital. The primary endpoint was overall survival. Results: The baseline liver status of the groups differed significantly and was most favorable for the HR group, followed by the RFA group, and then the TACE group. The 5-year overall survival rates were 93.6% in the HR group, 86.6% in the RFA group, and 74.2% in the TACE group (P = .023). However, after inverse probability weighting, weighted survival rates among the three groups were similar (5-year overall survival: 85.6% with HR, 87.6% with RFA, and 80.7% with TACE; P = .834). In multivariate Cox regression analysis, TACE showed a hazard ratio of 0.978 (95% confidence interval: 0.407, 2.347; P = .960) compared with HR and of 1.335 (95% confidence interval: 0.619, 2.879; P = .461) compared with RFA. Conclusion: TACE is an effective treatment that allows achievement of long-term survival rates comparable to those with HR and RFA in patients with small single-nodule hepatocellular carcinoma.