Risk factors of survival after percutaneous radiofrequency ablation of hepatocellular carcinoma

AIMS: This study aimed to determine the risk factors of survival in patients with hepatocellular carcinoma (HCC) undergoing percutaneous radiofrequency ablation (PRFA). PATIENTS AND METHODS: Between August 1999 and May 2005, 281 patients (250 males and 31 females) who were 33-80 years old (mean 65.3 years) received PRFA only or PRFA in combination with percutaneous ethanol injection (PEI) in our center. Patients were treated with PRFA or PEI by a percutaneous approach with ultrasound (US) guidance and were evaluated at regular intervals to determine disease recurrence and survival. The survival curves were constructed by the Kaplan-Meier method and compared by the log-rank test. The relative significance of the variables in the risk factors of overall survival was assessed by multivariate Cox proportional hazards regression analysis. RESULTS: At the end of the study, 189 patients were alive, and 92 were dead. Median survival was 48.7 months. The overall 1-, 3-, and 5-year survival rates were 89%, 54%, and 43%, respectively. The overall 1-, 3-, and 5-year survival rates for small tumor (size < or = 3cm) were 97.8%, 65.7%, 58.6%, respectively, for medium tumor (size 3.1-5cm) 94.1%, 57.1%, 37.1%, respectively, and for large tumor (size >5cm) 62.8%, 40.3%, 0%, respectively. Survival of patients treated with PRFA was dependent on tumor size (p<0.001; risk ratio [RR] 9.6, 95% CI 5.2-17.8), number of tumors (p=0.003; RR 1.6, 95% CI 1.2-2.0), combination with PEI (p=0.01; RR 0.6, 95% CI 0.4-0.9), Child-Pugh class (p=0.002; RR 2.0, 95% CI 1.3-3.0) and safety margin (p=0.0026; RR 0.6, 95% CI 0.4-0.9). CONCLUSIONS: PRFA is an effective treatment for HCC. This study showed after PRFA, tumor size, number of tumors, combination with PEI, safety margin, and Child-Pugh class were independent risk factors of survival.