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Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet].

Radiofrequency ablation in the treatment of small hepatocellular carcinoma: a meta analysis

JG Liu, YJ Wang, and Z Du.

Review published: 2010.

CRD summary

This review concluded that radiofrequency ablation did not decrease the number of overall recurrences and had no effect on survival when compared with surgical resection in a selected group of patients with small hepatocellular carcinoma. Significant heterogeneity among studies, unclear study quality and potential for bias in the review mean that the authors' conclusions should be interpreted with caution.

Authors' objectives

To compare survival and recurrence rates after radiofrequency ablation or surgical resection for the treatment of small hepatocellular carcinoma.

Searching

PubMed, CBM and CNKI were searched between January 1990 and December 2008. Search terms were described. Studies in English, French, German, Italian, Spanish, Danish, Dutch, Korean and Chinese were selected. Studies were identified from reference lists of papers and abstracts from recent international meetings.

Study selection

Studies that compared radiofrequency ablation (RFA) to surgical resection (hepatectomy) for treatment of small hepatocellular carcinoma (HCC) were selected.

Inclusion criteria were: patient suitable for surgical resection or RFA; minimum follow-up of 12 months; a single HCC less than 5cm in diameter or no more than three HCC less than 5cm in total; no extrahepatic metastasis; no radiologic evidence of invasion into the major portal or hepatic veins; good liver function (Child-Pugh Class A or B, with no history of encephalopathy, ascites refractory to diuretics or variceal bleeding); no previous treatment of HCC; and no recurrences where no tumour was found by spiral computed tomography and serum α-fetoprotein level when assessed every three months after treatment during the follow-up period. Studies that used non-commercial electrodes or palliative treatment were excluded.

The authors did not state how many reviewers screened studies for inclusion.

Assessment of study quality

Studies were scored for quality independently by two or three reviewers in accordance with a non-randomised controlled clinical trial quality evaluation standard. Only overall scores were reported.

Data extraction

Overall survival and recurrence rates were extracted by two or three reviewers independently using a standardised form. Where there was overlap between reports, data from the most detailed was included. Authors were contacted for additional details if required.

Methods of synthesis

To estimate the odds ratio (OR) and 95% confidence interval (95% CI) for survival and recurrence, meta-analysis was performed using either the Mantel-Haenszel fixed-effect model (no heterogeneity) or DerSimonian and Laird random-effects model (significant heterogeneity). Statistical heterogeneity was evaluated using I2 and Χ2. Funnel plots and Egger’s and Begg’s tests were used to test for publication bias.

Results of the review

Ten studies with 787 cases of RFA and 735 cases of surgical resection were included. The number of participants ranged from 44 to 434. Seven studies were retrospective (1,118 participants) and three were cohort studies (404 participants). Quality scores for all studies were between 7 and 9.

There was no statistical difference in survival at one year (OR 0.94, 95% CI 0.65 to 1.36, I2=0%; seven studies), three years (OR 0.92, 95% CI 0.56 to 1.51, I2=75.5%; eight studies) and the end of follow-up (OR 0.82, 95% CI 0.48 to 1.39, I2=78.5%; nine studies). There was no difference in recurrence at one year (OR 0.96, 95% CI 0.69 to 1.33, I2=54.2%; five studies) or three years (OR 1.19, 95% CI 0.63 to 2.27, I2=82.4%; six studies). Recurrence was higher (reported as lower in the abstract of the review) in the RFA group at the end of follow-up (OR 1.73, 95% CI 1.04 to 2.87, I2=73.1%; eight studies).

There was no evidence of publication bias.

Authors' conclusions

RFA did not decrease the number of overall recurrences and had no effect on survival when compared with surgical resection in a selected group of patients.

CRD commentary

The review question and inclusion criteria were clear. The search strategy appeared appropriate. The limitation to studies published in specific languages may have introduced some language bias into the review. The authors reported methods designed to reduce reviewer bias in the assessment of validity and extraction of data, but not for study selection. Appropriate methods were used in the synthesis of data and to assess statistical heterogeneity and publication bias.

Possible language and selection bias, significant heterogeneity and limited details on the included cohort and retrospective studies mean that these findings should be viewed with caution.

Implications of the review for practice and research

Practice: The authors stated that when conditions permit and under technically assured circumstances, RFA can be performed percutaneously, laparoscopically or during laparotomy and can partially replace surgical resection. For patients without the opportunity or who are unwilling to accept surgical treatment, RFA is an acceptable means of palliative care.

Research: The authors stated that large randomised controlled trials with longer follow-up are required.

Funding

Not stated

Bibliographic details

Liu JG, Wang YJ, Du Z. Radiofrequency ablation in the treatment of small hepatocellular carcinoma: a meta analysis. World Journal of Gastroenterology 2010; 16(27): 3450-3456. [PMC free article: PMC2904895] [PubMed: 20632451]

Indexing Status

Subject indexing assigned by NLM

MeSH

Bias (Epidemiology); Carcinoma, Hepatocellular /pathology /prevention & control /therapy; Catheter Ablation /methods /statistics & numerical data; Hepatectomy /methods /statistics & numerical data; Humans; Liver Neoplasms /pathology /prevention & control /therapy; Neoplasm Recurrence, Local; Odds Ratio; Sensitivity and Specificity; Survival Rate; Treatment Outcome

AccessionNumber

12010005678

Database entry date

06/04/2011

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.

CRD has determined that this article meets the DARE scientific quality criteria for a systematic review.

Copyright © 2014 University of York.

PMID: 20632451