Risk factors of survival after percutaneous radiofrequency ablation of hepatocellular carcinoma

This study aimed to determine the risk factors of survival in patients with hepatocellular carcinoma (HCC) undergoing percutaneous radiofrequency ablation (PRFA). 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. 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 ⩽3 cm) were 97.8%, 65.7%, 58.6%, respectively, for medium tumor (size 3.1–5 cm) 94.1%, 57.1%, 37.1%, respectively, and for large tumor (size >5 cm) 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). 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.