Necessity of prophylactic splenic hilum lymph node clearance for middle and upper third gastric cancer: a network meta-analysis

Background It remains controversial whether prophylactic No.10 lymph node clearance is necessary for gastric cancer. Thus, the present study aims to investigate the impact of prophylactic No.10 lymph node clearance on the perioperative complications and prognosis of upper and middle third gastric cancer. Methods A network meta-analysis to identify both direct and indirect evidence with respect to the comparison of gastrectomy alone (G-A), gastrectomy combination with splenectomy (G + S) and gastrectomy combination with spleen-preserving splenic hilar dissection (G + SPSHD) was conducted. We searched Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) for studies published before September 2018. Perioperative complications and overall survival were analyzed. Hazard ratios (HR) were extracted from the publications on the basis of reported values or were extracted from survival curves by established methods. Results Ten retrospective studies involving 2565 patients were included. In the direct comparison analyses, G-A showed comparable 5-year overall survival rate (HR: 1.1, 95%CI: 0.97–1.3) but lower total complication rate (OR: 0.37, 95%CI: 0.17–0.77) compared with G + S. Similarly, the 5-year overall survival rate between G + SPSHD and G + S was comparable (HR: 1.1, 95%CI: 0.92–1.4), while the total complication rate of G + SPSHD was lower than that of G + S (OR: 0.50, 95%CI: 0.28–0.88). In the indirect comparison analyses, both the 5-year overall survival rate (HR: 1.0, 95%CI: 0.78–1.3) and total complication rate (OR: 0.75, 95%CI: 0.29–1.9) were comparable between G-A and G + SPSHD. Conclusions Prophylactic No.10 lymph node clearance was not recommended for treatment of upper and middle third gastric cancer.