Three-field vs two-field lymph node dissection for esophageal cancer:A meta-analysis

AIM:To assess the effects of 3-field lymphadenectomy for esophageal carcinoma.METHODS:We conducted a computerized literature search of the Pub Med,Cochrane Controlled Trials Register,and EMBASE databases from their inception to present.Randomized controlled trials(RCTs)or observational epidemiological studies(cohort studies)that compared the survival rates and/or postoperative complications between 2-field lymphadenectomy(2FL)and3-field lymphadenectomy(3FL)for esophageal carcinoma with R0 resection were included.Meta-analysis was conducted using published data on 3FL vs 2FL in esophageal carcinoma patients.End points were 1-,3-,and 5-year overall survival rates and postoperativecomplications,including recurrent nerve palsy,anastomosis leak,pulmonary complications,and chylothorax.Subgroup analysis was performed on the involvement of recurrent laryngeal lymph nodes.RESULTS:Two RCTs and 18 observational studies with over 7000 patients were included.There was a clear benefit for 3FL in the 1-(RR=1.16;95%CI:1.09-1.24;P<0.01),3-(RR=1.44;95%CI:1.19-1.75;P<0.01),and 5-year overall survival rates(RR=1.37;95%CI:1.18-1.59;P<0.01).For postoperative complications,3FL was associated with significantly more recurrent nerve palsy(RR=1.43;95%CI:1.28-1.60;P=0.02)and anastomosis leak(RR=1.26;95%CI:1.05-1.52;P=0.09).In contrast,there was no significant difference for pulmonary complications(RR=0.93;95%CI:0.75-1.16,random-effects model;P=0.27)or chylothorax(RR=0.77;95%CI:0.32-1.85;P=0.69).CONCLUSION:This meta-analysis shows that 3FL improves overall survival rate but has more complications.Because of the high heterogeneity among outcomes,definite conclusions are difficult to draw.