Cryoablation Provides Superior Local Control of Primary Hepatocellular Carcinomas of >2 Cm Compared with Radiofrequency Ablation and Microwave Coagulation Therapy: an Underestimated Tool in the Toolbox

Background: Although cryoablation (Cryo) has been advocated as an effective locoregional therapy for hepatocellular carcinoma (HCC), few studies have compared the outcomes with those of radiofrequency ablation (RFA) and microwave coagulation therapy (MCT).

Methods: Consecutive patients with primary HCCs of <5 cm received Cryo or RFA/MCT between 1998 and 2011 and were monitored for local recurrence (defined as a recurrent tumor at or in direct contact with the ablated area) and overall complication rates.

Results: The median tumor size was 2.5 cm in the Cryo group (n = 55) and 1.9 cm in the RFA/MCT group (n = 64; P < 0.001), but other patient characteristics were similar. Multivariate Cox regression analysis revealed Cryo as the only independent factor for improved 2-year local recurrence-free survival, with a hazard ratio (HR) of 0.3 (95 % confidence interval, 0.1-0.9; P = 0.02). Tumor diameter was a negative indicator of local recurrence-free survival (HR, 2.0; 95 % confidence interval, 1.1-3.5; P = 0.02). Subgroup analysis of patients with tumors of >2 cm demonstrated significantly better local recurrence rates in the Cryo group compared with the RFA/MCT group (21 vs. 56 % at 2 years; P = 0.006). Overall complication rates and incidences of Clavien-Dindo classification grade ≥ III were identical (both P = 1.00). No in-hospital mortality occurred.

Conclusions: Appropriate use of Cryo, as shown in this series, is safe and provides significantly improved local control for the treatment of primary HCCs of >2 cm compared with RFA/MCT.