title: Risk factors of survival after percutaneous radiofrequency ablation of hepatocellular carcinoma.
abstract: OBJECTIVE
  This study aimed to determine the risk factors of survival in patients with hepatocellular carcinoma (HCC) undergoing percutaneous radiofrequency ablation (PRFA).
  
  
  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.
authors.affiliation: Department of Hepatobiliary Surgery, Cancer Centre of Sun Yat-Sen University, 651 Dongfeng Road East, Guangzhou 510060, China.
authors.forename: Zhen-Wei
authors.initials: ZW
authors.lastname: Peng
authors.forename: Yao-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.forename: Min-Shan
authors.initials: MS
authors.lastname: Chen
authors.forename: Hui-Hong
authors.initials: HH
authors.lastname: Liang
authors.forename: Jin-Qing
authors.initials: JQ
authors.lastname: Li
authors.forename: Ya-Qi
authors.initials: YQ
authors.lastname: Zhang
authors.forename: Wan Y
authors.initials: WY
authors.lastname: Lau
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage; D006528:Carcinoma, Hepatocellular / Q000401:mortality* / Q000601:surgery; D017115:Catheter Ablation / Q000379:methods*; D002681:China / Q000453:epidemiology; D000431:Ethanol / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015552:Injections, Intralesional; D008113:Liver Neoplasms / Q000401:mortality* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
chemical_list: D000891:Anti-Infective Agents, Local; D000431:Ethanol