Hospital and Surgeon Volume versus Outcomes after Colorectal Cancer Surgery: Comprehensive Umbrella Review

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 centralisation 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 synthesises the evidence on volume-outcome associations in colorectal surgery. Methods An umbrella review (PRISMA 2020) was conducted to evaluate systematic reviews and meta-analyses on hospital/surgeon volume-outcome relationship in colorectal cancer. Cochrane Library, PubMed, EMBASE and MEDLINE were searched to 1 Oct 2025. Volume definitions and outcomes were extracted and meta-analysed by subgroup. AMSTAR2 and ROBIS were conducted for bias. Results A total of 150 unique records were identified, with 10 systematic reviews meeting the inclusion criteria. High versus low-volume hospitals on post-operative mortality following resection demonstrated an inverse relationship for rectal cancer, fixed and random effects (OR: 0.73 [0.64 – 0.82]), colon cancer fixed (OR: 0.74 [0.70 – 0.78]) and random effects (OR: 0.75 [0.69 – 0.81]) and colorectal cancer, fixed and random effects (OR: 0.77 [0.67 – 0.88]) High versus low-volume surgeons on post-operative mortality following resection demonstrated an inverse relationship for rectal cancer, fixed and random effects (OR: 0.69 [0.59 – 0.81]), colon cancer, fixed (OR: 0.70 [0.63 – 0.77]) and random effects (OR: 0.68 [0.55 – 0.85]) and colorectal cancer, fixed and random effects (OR: 0.67 [0.60 – 0.74]). There were no consistent significant differences in rates of the secondary outcomes (anastomotic leak rate, permanent stoma formation, local recurrence rate, APER rate). 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 versus low-volume hospitals and surgeons is yet to be elucidated due to the heterogeneity of existing volume definitions. Future studies are required to confirm a threshold for this dose response relationship.