The Influence of Hospital and Surgeon Volume on Survival and Local Control in Rectal Cancer: Long-term Results of the CAO/ARO/AIO-94 Trial.

738 Background: The association of hospital and surgeon volume with the outcome of rectal cancer patients is under debate. In this study the long-term influence of the hospital as well as the surgeon volume on overall survival and local recurrence were investigated. Methods: In a post-hoc analysis of the randomized phase III CAO/ARO/AIO-94 trial after a follow-up of more than 10 years, 799 patients with locally advanced rectal cancers were evaluated. Survival and local recurrence rates were stratified by the hospital recruitment volume (≤20 vs. 21-90 vs. > 90 patients) and by the surgeon volume (≤10 vs. 11-50 vs. > 50 procedures). Results: Patients treated in „high-volume“ hospitals had a longer overall survival than those treated in hospitals with medium or low treatment volume (p = 0.03). The surgeon volume was significantly associated with decreased local recurrences (p = 0.01) but had no influence on overall survival. The effect of neoadjuvant chemoradiation on local control was the strongest in patients being operated by medium-volume surgeons. Conclusions: Patients with locally advanced rectal cancers might benefit from treatment in in specialized high-volume hospitals. In particular, the surgeon volume had significant influence on local control.