D2 lymphadenectomy with complete mesogastrium excision vs. conventional D2 gastrectomy for advanced gastric cancer

Background: The complete mesogastrium excision (CME) based on D2 radical gastrectomy is believed to significantly reduce the local-regional recurrence compared with D2 radical gastrectomy in advanced gastric cancer, and it is widely used in China. This study aimed to explore whether D2 + CME is superior to D2 on surgical outcomes during gastrectomy from Chinese data.Methods: Feasible studies comparing the D2 + CME (D2 + CME group) and D2 (D2 group) published up to March 2020 are searched from electronic databases. The data showing surgical and complication outcomes are extracted to be pooled and analyzed.Results: Fourteen records including 1352 patients were included. The D2 + CME group had a shorter mean operative time (weighted mean difference [WMD] = -16.72 min, 95% confidence interval [CI]: -26.56 to - 6.87 min,P < 0.001), lower mean blood loss (WMD = -39.08 mL, 95% CI: -49.94 to -28.21 mL,P < 0.001), higher mean number of retrieved lymph nodes (WMD = 2.13, 95% CI: 0.58-3.67,P = 0.007), shorter time to first flatus (WMD =-0.31 d, 95% CI: -0.53 to - 0.10 d,P = 0.005), and postoperative hospital days (WMD =-1.09, 95% CI: -1.92 to -0.25,P = 0.010) than the D2 group. Subgroup analysis suggested that the advantages from the D2 + CME group were obvious in traditional open radical gastrectomy, proximal gastrectomy, and distal gastrectomy compared with D2 group. The evaluations of post-operative complications showed that the patients who underwent D2 + CME had a lower incidence of post-operative complications than the patients who underwent D2 surgery alone (relative risk [RR] = 0.65, 95% CI: 0.45-0.87,P = 0.003). The D2 radical gastrectomy plus CME improved 3-year overall survival (OS) (RR = 1.16, 95% CI: 1.02-1.32,P = 0.020) and lowered the local recurrence rate (RR = 0.51, 95% CI: 0.28-0.94,P = 0.030). The patients undergoing laparoscopic surgery or total gastrectomy had more significant advantages compared between D2 + CME and D2 groups in 3-year OS.Conclusion: The data from China show that D2 radical gastrectomy plus CME are reliable procedures and safety compared to D2 radical gastrectomy with faster recovery, lower risk, and better prognosis.