The Effect of Facility Volume on Survival Following Proctectomy for Rectal Cancer.

Background: Prior studies assessing colorectal cancer survival have reported better outcomes when operations are performed at high-volume centers. These studies have largely been cross-sectional, making it difficult to interpret their estimates. We aimed to assess the effect of facility volume on survival following proctectomy for rectal cancer.

Methods: Using data from the National Cancer Database, we included all patients with complete baseline information who underwent proctectomy for non-metastatic rectal cancer between 2004 and 2016. Facility volume was defined as the number of rectal cancer cases managed at the treating center in the calendar year prior to the patient's surgery. Overall survival estimates were obtained for facility volumes ranging from 10 to 100 cases/year. Follow-up began on the day of surgery and continued until loss to follow-up or death.

Results: A total of 52,822 patients were eligible. Patients operated on at hospitals with volumes of 10, 30, and 50 cases/year had similar distributions of grade, clinical stage, and neoadjuvant therapies. 1-, 3-, and 5-year survival all improved with increasing facility volume. One-year survival was 94.0% (95% CI: 93.7, 94.3) for hospitals that performed 10 cases/year, 94.5% (95% CI: 94.2, 94.7) for 30 cases/year, and 94.8% (95% CI: 94.5, 95.0) for 50 cases/year. Five-year survival was 68.9% (95% CI: 68.0, 69.7) for hospitals that performed 10 cases/year, 70.8% (95% CI: 70.1, 71.5) for 30 cases/year, and 72.0% (95% CI: 71.2, 72.8) for 50 cases/year.

Conclusions: Treatment at a higher volume facility results in improved survival following proctectomy for rectal cancer, though the small benefits are less profound than previously reported.