Radiofrequency ablation for colorectal liver metastases: prognostic factors in non-surgical candidates

To determine prognostic factors in patients with colorectal liver metastases who were not surgical candidates and received liver radiofrequency (RF) ablation. RF ablation was done for 141 colorectal liver metastases in 84 patients. There were 63 (75.0 %, 63/84) males and 21 (25.0 %, 21/84) females, with a mean age of 64.6 +/- A 10.3. The mean maximum tumor diameter was 2.3 +/- A 1.4 cm (range 0.5-9.0 cm). Extrahepatic metastases were associated at the time of liver RF ablation in 23 patients (27.4 %, 23/84), and 12 (14.3 %, 12/84) had lung metastases considered controllable by planned lung RF ablation. Prognostic factors were evaluated by univariate and multivariate analyses. There was no procedure-related mortality. The 1-, 3-, and 5-year overall survival rates were 90.6 % (95 %CI, 83.9-97.2 %), 44.9 % (95 %CI, 31.8-57.9 %), and 20.8 % (95 %CI, 7.3-34.3 %), respectively, with a median survival of 34.9 months. The univariate analysis showed that tumor diameter larger than 3 cm, tumor multiplicity, uncontrollable extrahepatic disease, and previous chemotherapy history were significantly worse prognostic factors. The former three factors remained significant for worse prognosis in the multivariate Cox model. Extrahepatic disease was not a prognostic factor when it could be controlled. Tumor size and number, and uncontrollable extrahepatic metastases were significant prognostic factors.