Three-field versus two-field lymphadenectomy for esophageal squamous cell carcinoma : A long-term survival meta-analysis

Background: In the setting of esophageal squamous cell carcinoma, controversy exists regarding the optimal extent of lymphadenectomy, while conclusive evidence regarding the advantages of 3-field versus 2-field lymphadenectomy remains controversial. The purpose of the present meta-analysis was to investigate the effect of 3-field lymphadenectomy versus 2-field lymphadenectomy on overall survival. Methods: Systematic review and meta-analyses were computed to compare 3-field lymphadenectomy versus 2-field lymphadenectomy in the setting of esophageal squamous cell carcinoma. Risk ratio, weighted mean difference, hazard ratio, and restricted mean survival time difference were used as pooled effect size measures. Results: Fourteen studies (3,431 patients) were included. Overall, 1,664 (48.8%) patients underwent 3-field lymphadenectomy, and 1,767 (51.5%) underwent 2-field lymphadenectomy. Three-field lymphadenectomy was associated with a significantly improved 5-year overall survival (hazard ratio: 0.80; 95% confidence interval 0.71–0.90; P < .001). The restricted mean survival time difference showed a statistically significant difference between 3-field lymphadenectomy versus 2-field lymphadenectomy up to 48 months (1.6 months; P = .04), however, no significant differences were found at 60-month follow-up (1.2 months; P = .14). No significant differences were found in term of postoperative mortality, anastomotic leak, pulmonary complications, chylothorax, and recurrent nerve palsy. Conclusion: For resectable esophageal squamous cell carcinoma, 3-field lymphadenectomy seems associated with a slight trend toward improved 5-year overall survival; however, its clinical benefit remains limited.