Cryoablation compared with radiofrequency ablation and microwave coagulation therapy for the local control of primary hepatocellular carcinoma.

Abstract

286 Background: Although cryoablation (Cryo) has been advocated as an effective local treatment for hepatocellular carcinoma (HCC), data are lacking regarding its outcomes in comparison with radiofrequency ablation (RFA) and microwave coagulation therapy (MCT). The aim of this study was to clarify the benefits and disadvantages of each modality for primary HCC. Methods: We reviewed outcomes of 120 patients with primary HCCs (< 5cm) who underwent local treatment (Cryo: n = 55 and RFA/MCT: n = 65) between 1998 and 2011. The primary endpoint was local recurrence free survival (LRFS). The secondary endpoints were complication rates and the length of hospital stay. Results: Age, sex, Child-Pugh score, and background liver disease were identical between both groups. The Cryo group had larger tumors (mean ± standard error tumor size: Cryo 2.55 ± 0.75 cm vs. RFA/MCT 1.96 ± 0.72cm, p < 0.001). The LRFS was higher in the Cryo group than in RFA/MCT group (2270.0 ± 240.8 days vs. 1940.7 ± 269.5 days: p = 0.116). The Cox proportional hazards multivariate analysis revealed that Cryo as the treatment of choice was an independent predictive indicator of improved LRFS (HR, 0.403 [95% CI: 0.202−0.807], P = 0.010). On the contrary, tumor size (for each 1 cm increase, HR, 1.635 [95% CI: 1.038–2.574], p = 0.034) and Child-Pugh score ≥ 6 (HR, 2.166 [95% CI: 1.179 – 3.979], p = 0.013) were negative prognostic factors for LRFS. Subgroup analysis showed that the LRFS for tumors ≤ 2 cm was similar between the 2 groups. However, if the tumor size was greater than 2 cm, the LRFS of the Cryo group was superior to RFA/MCT (2400.0 ± 287.4 days vs. 1177.9 ± 366.5 days: p = 0.004). The complication rates (Cryo 10.9% vs. RFA/MCT 10.8%: p = 0.980) and the length of hospital stay (9.45 ± 5.33 days vs. 9.52 ± 5.90 days: p = 0.947) were similar in both groups. No mortality was observed in the entire cohort. Conclusions: Cryo provides significantly higher chance of local control for primary HCCs compared with RFA/MCT, particularly if the tumor size exceeds 2 cm. Associated risks are at least equivalent to those of RFA/MCT even in patients with marginal to poor liver function. Cryo is a promising local ablative option in an era of rising incidence of HCC.