Brief Article
Copyright ©2014 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Feb 14, 2014; 20(6): 1585-1593
Published online Feb 14, 2014. doi: 10.3748/wjg.v20.i6.1585
Percutaneous radiofrequency ablation for early hepatocellular carcinoma: Risk factors for survival
Luciana Kikuchi, Marcos Menezes, Aline L Chagas, Claudia M Tani, Regiane SSM Alencar, Marcio A Diniz, Venâncio AF Alves, Luiz Augusto Carneiro D’Albuquerque, Flair José Carrilho
Luciana Kikuchi, Aline L Chagas, Claudia M Tani, Regiane SSM Alencar, Marcio A Diniz, Luiz Augusto Carneiro D’Albuquerque, Flair J Carrilho, São Paulo Clínicas Liver Cancer Group, Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo 01246000, Brazil
Marcos Menezes, São Paulo Clínicas Liver Cancer Group, Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Department of Radiology, University of São Paulo School of Medicine, São Paulo 01246000, Brazil
Venâncio AF Alves, São Paulo Clínicas Liver Cancer Group, Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Department of Pathology, University of São Paulo School of Medicine, São Paulo 01246000, Brazil
Author contributions: Kikuchi L and Menezes M contributed equally to this work; Kikuchi L, Chagas AL and Menezes M designed the study; Kikuchi L, Menezes M, Chagas AL, Tani CM and Alencar RSSM performed the research; Kikuchi L, Menezes M, Diniz MA, Alves VAF, D’Albuquerque LAC and Carrilho FJ analyzed the data; Kikuchi L and Menezes M wrote the article; Alves VAF, D’Albuquerque LAC and Carrilho FJ revised the article for critical intellectual content; all authors read and approved the final version of the article for publication.
Supported by Alves de Queiroz Family Fund for Research
Correspondence to: Luciana Kikuchi, MD, São Paulo Clínicas Liver Cancer Group, Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas, Department of Gastroenterology, University of São Paulo School of Medicine, 255 Arnaldo Avenue, São Paulo 01246000, Brazil. lucianakikuchi@usp.br
Telephone: + 55-11-38934406 Fax: + 55-11-26617830
Received: October 1, 2013
Revised: November 12, 2013
Accepted: November 28, 2013
Published online: February 14, 2014
Processing time: 138 Days and 18.4 Hours
Abstract

AIM: To evaluate outcomes of radiofrequency ablation (RFA) therapy for early hepatocellular carcinoma (HCC) and identify survival- and recurrence-related factors.

METHODS: Consecutive patients diagnosed with early HCC by computed tomography (CT) or magnetic resonance imaging (MRI) (single nodule of ≤ 5 cm, or multi- (up to 3) nodules of ≤ 3 cm each) and who underwent RFA treatment with curative intent between January 2010 and August 2011 at the Instituto do Câncer do Estado de São Paulo, Brazil were enrolled in the study. RFA of the liver tumors (with 1.0 cm ablative margin) was carried out under CT-fluoro scan and ultrasonic image guidance of the percutaneous ablation probes. Procedure-related complications were recorded. At 1-mo post-RFA and 3-mo intervals thereafter, CT and MRI were performed to assess outcomes of complete response (absence of enhancing tissue at the tumor site) or incomplete response (enhancing tissue remaining at the tumor site). Overall survival and disease-free survival rates were estimated by the Kaplan-Meier method and compared by the log rank test or simple Cox regression. The effect of risk factors on survival was assessed by the Cox proportional hazard model.

RESULTS: A total of 38 RFA sessions were performed during the study period on 34 patients (age in years: mean, 63 and range, 49-84). The mean follow-up time was 22 mo (range, 1-33). The study population showed predominance of male sex (76%), less severe liver disease (Child-Pugh A, n = 26; Child-Pugh B, n = 8), and single tumor (65%). The maximum tumor diameters ranged from 10 to 50 mm (median, 26 mm). The initial (immediately post-procedure) rate of RFA-induced complete tumor necrosis was 90%. The probability of achieving complete response was significantly greater in patients with a single nodule (vs patients with multi-nodules, P = 0.04). Two patients experienced major complications, including acute pulmonary edema (resolved with intervention) and intestinal perforation (led to death). The 1- and 2-year overall survival rates were 82% and 71%, respectively. Sex, tumor size, initial response, and recurrence status influenced survival, but did not reach the threshold of statistical significance. Child-Pugh class and the model for end-stage liver disease score were identified as predictors of survival by simple Cox regression, but only Child-Pugh class showed a statistically significant association to survival in multiple Cox regression analysis (HR = 15; 95%CI: 3-76 mo; P = 0.001). The 1- and 2-year cumulative disease-free survival rates were 65% and 36%, respectively.

CONCLUSION: RFA is an effective therapy for local tumor control of early HCC, and patients with preserved liver function are the best candidates.

Keywords: Hepatocellular carcinoma; Radiofrequency ablation; Overall survival; Disease-free survival

Core tip: Radiofrequency ablation (RFA) is widely recognized as an effective therapy for early stage hepatocellular carcinoma (HCC) in patients who are not suitable candidates for surgical resection, such as those with decompensated liver function or portal hypertension. Reports from Brazil of clinical experience with RFA management of HCC are rare. This study evaluated 34 consecutive patients with early HCC treated with RFA at a single Brazilian hospital. RFA was efficacious for promoting local tumor control and positive outcome was related to preserved liver function. Careful evaluation of liver function may help to identify the best candidates for this procedure.