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Feasibility and safety of laparoscopic gastrectomy for gastric cancer: a meta analysis of five prospective randomized controlled trials |
Yao GL, Yu JP, Yao QY |
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CRD summary This review concluded that laparoscopic gastrectomy was feasible and safe for early stage stomach cancer compared with open gastrectomy. Given the potential for bias in the review process, substantial variation, and the limited poor quality evidence, the authors' conclusions should be treated with caution. Authors' objectives To assess the feasibility and safety of laparoscopic gastrectomy for early stage gastric cancer. Searching PubMed, EMBASE, Web of Knowledge, Chinese Journal Full-text Database and Wanfang were searched from January 1994 up to December 2009 for studies published in English or Chinese; search terms were reported. Study selection Prospective randomised controlled trials (RCTs) that compared laparoscopic with open gastrectomy were eligible for inclusion. Eligible outcomes were at least one of the following: operating time, intraoperative blood loss, time to resumption of oral intake, length of hospital stay, number of lymph nodes removed, postoperative complications, postoperative morbidity and tumour recurrence. In the included trials, the mean age of participants ranged from 55 to 64 years. The mean proportion of men ranged from 57% (laparoscopic gastrectomy) to 67% (open gastrectomy). Included trials used either D1 or D2 lymph node dissection. Trials were undertaken in Japan, Korea and Italy. The authors did not state how many reviewers selected studies for the review. Assessment of study quality Trials were assessed for quality using a modified Jadad scale with a maximum score of 7 points; criteria included randomisation, allocation concealment, blinding, experimental blinding, and withdrawals and drop-outs. Trials with an overall score of 1 to 3 were considered poor quality; trials with scores above 3 were considered good quality. The authors did not state how many reviewers assessed studies for quality. Data extraction Data were extracted on the eligible outcomes. Risk ratios (RRs) or risk differences (RDs), with 95% confidence intervals (CIs), were calculated for dichotomous outcomes. Mean differences (MDs) and 95% confidence intervals were calculated for continuous outcomes. The authors did not state how many reviewers extracted data. Methods of synthesis Trials were pooled in meta-analyses using a fixed-effect model for homogeneous data, otherwise a random-effects model was used. Summary effect risk ratios and risk differences were calculated using the Mantel-Haenszel method. Weighted mean differences (WMDs) were calculated using inverse variance. Heterogeneity was assessed using Χ² and Ι². Subgroup analysis was undertaken according to the different methods for removal of lymph nodes. Sensitivity analysis was undertaken to test the robustness of the findings by excluding trials that caused asymmetry in the funnel plots. Publication bias was assessed by inspection of funnel plots. Results of the review Five RCTs (326 patients) were included in the review. Three trials received summary Jadad scores of 3 points, one had a score of 4 points, and one had a score of 5 points. Two trials had adequate randomisation and allocation concealment, but none had blinding. No participants were lost to follow-up, but the number of patients who dropped out or withdrew were not reported. Follow-up ranged from four to 52 months (where reported). Compared with open gastrectomy, laparoscopic gastrectomy was associated with significantly longer operation time (WMD 81.6 minutes, 95% CI 49.64 to 113.56; Ι²=96%; five trials), and fewer lymph nodes removed (WMD -4.79 nodes, 95% CI -6.79 to -2.79; Ι²=0%; five trials). Compared with open gastrectomy, laparoscopic gastrectomy was associated with significantly less blood loss (WMD -121.37mLs, 95% CI -174.68 to -68.06; Ι²=73%; five trials) and shorter hospital stay (WMD -2.41 days, 95% CI -4.74 to -0.08; Ι²=88%; five trials). There was no evidence of a significant difference between the groups for the time to resumption of oral intake, postoperative complications, postoperative morbidity and tumour recurrence. Sensitivity analysis excluding the trial that caused asymmetry in the funnel plot for intraoperative blood loss, indicated that the findings were not markedly changed. Subgroup analysis suggested that in D1 lymph node dissection, intraoperative blood loss was significantly reduced with laparoscopic gastrectomy compared with open gastrectomy (three trials), but in D2 lymph node dissection there was no evidence of a significant difference in intraoperative blood loss between groups (two trials). Authors' conclusions Laparoscopic gastrectomy for early stage gastric cancer was feasible and safe. CRD commentary The review addressed a clear research question. The inclusion criteria were specified, but there were no specific inclusion criteria that limited patients to early stage gastric cancer. A wide range of databases were searched for studies published in English or Chinese, so language and publication bias could not be ruled out. Formal assessment of publication bias indicated that bias was likely, but there were too few trials to reliably reach a conclusion. The authors did not report the methods used for selection of studies, assessment of study quality or data extraction, so reviewer error and bias in these processes could not be excluded. An appropriate tool was used for quality assessment, but included trials were generally of poor quality and none were blinded, so the potential for bias could not be ruled out. Synthesis of trials and assessment of heterogeneity was appropriate. Substantial heterogeneity was identified for almost all outcomes, so it was difficult to determine the reliability of the results. Sensitivity and subgroup analyses were undertaken to attempt to explain some aspects of heterogeneity, but only one sensitivity analysis was reported. It was not possible to determine whether results were altered by exclusion of other trials that were outliers in the funnel plots for other outcomes. Given the potential for bias in the review process, substantial heterogeneity, and the limited poor quality evidence, the authors' conclusions should be treated with caution. Implications of the review for practice and research Practice: The authors stated that the indications for laparoscopic gastrectomy were gastric cancer patients with tumour infiltration depth within T2 and cancer that had not metastasised, but these conclusions were not based on the findings of the review. They also stated that hand-assisted laparoscopic gastrectomy was the best option for a beginner. Research: The authors stated that further prospective RCTs of good quality should include large sample sizes and multiple centres. Studies should investigate numbers of lymph nodes removed, type of lymph node dissection and type of anastomosis. Bibliographic details Yao GL, Yu JP, Yao QY. Feasibility and safety of laparoscopic gastrectomy for gastric cancer: a meta analysis of five prospective randomized controlled trials. Journal of Clinical Rehabilitative Tissue Engineering Research 2010; 14(46): 8726-8731 Indexing Status Subject indexing assigned by CRD MeSH Gastrectomy; Humans; Laparoscopy; Stomach Neoplasms AccessionNumber 12011002564 Date bibliographic record published 21/09/2011 Date abstract record published 23/08/2012 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. |
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