Hospital volume matters: a meta-analysis of mortality after colorectal cancer surgery

BACKGROUND: Postoperative mortality serves as a critical indicator for assessing surgical safety in patients undergoing colorectal cancer surgery; however, the relationship between annually hospital surgical case volume and postoperative mortality remains unclear. Here, we aimed to investigate the volume-outcome relationship for colorectal cancer surgery and to identify potential thresholds for high-volume hospitals. METHODS: Studies reporting the association between hospital volume and postoperative mortality in colorectal cancer patients undergoing colorectal cancer surgery were systematically screened up to June 2025. The highest versus lowest categories of hospital volume were pooled using random effects models in colon and rectum resection, respectively. The volume-outcome association between hospital volume and mortality after colon and rectum resection were analyzed. RESULTS: Forty-five eligible studies were identified. Postoperative mortality risk in colorectal cancer patients undergoing colon resection and rectum resection were decreased by 27% and 25% in higher-volume compared with lower-volume hospitals, respectively. Volume-outcome analysis indicated that there had negative correlation between hospital volume and postoperative mortality risk in both colon and rectum resection. And the risk of postoperative mortality and mortality rate plateaued once hospitals performed ≥30 annually in rectum resection. However, similar threshold was not found in colon resection. CONCLUSIONS: Current findings suggest that higher-volume hospitals reduce the risk of mortality after colorectal cancer surgery. Importantly, a threshold of 30 rectum resection per year may be defined as a higher-volume hospital for rectal cancer.