Association between hospital surgical case volume and postoperative mortality in patients undergoing gastrectomy for gastric cancer: a systematic review and meta-analysis

BACKGROUND: Postoperative mortality is an important indicator for evaluating surgical safety. Postoperative mortality is influenced by hospital volume; however, this association is not fully understood. This study aimed to investigate the volume-outcome association between the hospital surgical case volume for gastrectomies per year (hospital volume) and the risk of postoperative mortality in patients undergoing a gastrectomy for gastric cancer. METHODS: Studies assessing the association between hospital volume and the postoperative mortality in patients who underwent gastrectomy for gastric cancer were searched for eligibility. Odds ratios were pooled for the highest versus lowest categories of hospital volume using a random-effects model. The volume-outcome association between hospital volume and the risk of postoperative mortality was analyzed. The study protocol was registered with Prospective Register of Systematic Reviews (PROSPERO). RESULTS: Thirty studies including 586 993 participants were included. The risk of postgastrectomy mortality in patients with gastric cancer was 35% lower in hospitals with higher surgical case volumes than in their lower-volume counterparts (odds ratio: 0.65; 95% CI: 0.56-0.76; P <0.001). This relationship was consistent and robust in most subgroup analyses. Volume-outcome analysis found that the postgastrectomy mortality rate remained stable or was reduced after the hospital volume reached a plateau of 100 gastrectomy cases per year. CONCLUSIONS: The current findings suggest that a higher-volume hospital can reduce the risk of postgastrectomy mortality in patients with gastric cancer, and that greater than or equal to 100 gastrectomies for gastric cancer per year may be defined as a high hospital surgical case volume.