Hospital and surgeon volumeoutcomes after colorectal cancer surgery: umbrella review and meta-analysis

Abstract

Abstract Background An inverse relationship between surgical volume and outcomes has been suggested, with higher-volume hospitals and surgeons achieving better results, prompting debate over the centralization of surgical services. However, minimum volume thresholds are unclear, and volume is a poor proxy for quality. Despite the significant global burden of colorectal cancer, the benefits of high-volume care remain uncertain. This umbrella review synthesized the evidence on volume–outcome associations in colorectal surgery. s1 Methods An umbrella review (PRISMA 2020) was conducted to evaluate systematic reviews and meta-analyses of the hospital/surgeon volume–outcome relationship in colorectal cancer. The Cochrane Library, PubMed, Embase, and MEDLINE were searched to 1 October 2025. Volume definitions and outcomes were extracted and meta-analysed by subgroup. A MeaSurement Tool to Assess Systematic Reviews 2 and Risk of Bias in Systematic Reviews were used for analysis of bias. s2 Results A total of 150 unique records was identified, with 10 systematic reviews meeting the inclusion criteria. High-low-volume hospitals demonstrated an inverse relationship in terms of postoperative mortality following resection for rectal cancer (fixed- and random-effects models: odds ratio 0.73, 95 per cent confidence interval 0.64 to 0.82), colon cancer (fixed-effect model: odds ratio 0.74, 0.70 to 0.78; random-effects model: odds ratio 0.75, 0.69 to 0.81), and colorectal cancer (fixed- and random-effects models: odds ratio 0.77, 0.67 to 0.88). High-low-volume surgeons demonstrated an inverse relationship with respect to postoperative mortality following resection for rectal cancer (fixed- and random-effects models: odds ratio 0.69, 0.59 to 0.81), colon cancer (fixed-effect model: odds ratio 0.70, 0.63 to 0.77; random-effects model: odds ratio 0.68, 0.55 to 0.85), and colorectal cancer (fixed- and random-effects models: odds ratio 0.67, 0.60 to 0.74). There were no consistent significant differences in rates of the secondary outcomes (anastomotic leak rate, permanent stoma formation, local recurrence rate, rate of abdominoperineal excision of the rectum). s3 Conclusion High-volume hospitals and surgeons are associated with both improved short- and long-term outcomes for patients undergoing colorectal cancer surgery. However, a specific cut-off definition for high-low-volume hospitals and surgeons is yet to be elucidated owing to the heterogeneity of existing volume definitions. Future studies are required to confirm a threshold for this dose–response relationship. s4 The volume–outcome relationship in colorectal cancer surgery remains controversial, with no agreed minimum volume thresholds. This umbrella review found that higher hospital and surgeon volumes were consistently associated with lower postoperative mortality across colorectal cancer subtypes. Higher surgeon volume showed the most consistent association with improved overall survival. No consistent benefit was observed for secondary outcomes including anastomotic leak rate, permanent stoma formation, local recurrence, or rate of abdominoperineal excision of the rectum. teaser