Combined transarterial chemoembolization and radiofrequency ablation for subphrenic versus nonsubphrenic hepatocellular carcinoma: a propensity score matched study.

Purpose: To compare therapeutic outcomes of combined transarterial chemoembolization (TACE) and radiofrequency ablation (RFA) treatment for small hepatocellular carcinoma (HCC) in subphrenic versus nonsubphrenic locations by propensity score matching.

Methods: This retrospective study included 293 patients with single HCC (≤ 3 cm) ineligible for ultrasound-guided RFA who received iodized oil TACE and subsequent RFA between June 2010 and January 2017. The patients were divided into two groups according to the tumor location: subphrenic (n = 99) and nonsubphrenic (n = 194). Subphrenic HCC was defined as a tumor abutting the diaphragm. Local tumor progression (LTP) and overall survival (OS) rates were compared by propensity score matching. Procedure-related complications were also assessed.

Results: Matching yielded 93 matched pairs of patients. In the matched cohorts, cumulative 1-, 3-, and 5-year LTP rates were 5.4%, 12.1%, and 12.1% in the subphrenic group and 1.1%, 7.5%, and 8.6% in the nonsubphrenic group, respectively, with no significant differences (p = 0.278). Corresponding OS rates were 100%, 80.2%, and 71.3% in the subphrenic group and 97.9%, 88.1%, and 75.6% in the nonsubphrenic group, respectively, with no significant differences (p = 0.308). The subphrenic location was not a significant risk factor for LTP and OS in multivariate analysis. There were no significant differences in complication rates between the two groups (p > 0.05).

Conclusion: The therapeutic outcomes of combined TACE and RFA for small subphrenic HCC were similar to those for nonsubphrenic HCC. The combination therapy seems to be an effective and safe method in treating small subphrenic HCC.