The long-term influence of hospital and surgeon volume on local control and survival in the randomized German Rectal Cancer Trial CAO/ARO/AIO-94.

Background: The association of treatment volume and oncological outcome of rectal cancer patients undergoing multidisciplinary treatment is subject of an ongoing debate. Prospective data on long-term local control and overall survival (OS) are not available so far. This study investigated the long-term influence of hospital and surgeon volume on local recurrence (LR) and OS in patients with locally advanced rectal cancers.

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 stage II/III rectal cancers were evaluated. LR-rates and OS were stratified by hospital recruitment volume (≤20 vs. 21-90 vs. >90 patients) and by surgeon volume (≤10 vs. 11-50 vs. >50 procedures).

Results: Patients treated in high-volume hospitals had a longer OS than those treated in hospitals with medium or low treatment volume (p = 0.03). The surgeon volume was adversely associated with LR (p = 0.01) but had no influence on overall survival. The positive effect of neoadjuvant chemoradiation (CRT) on local control was the strongest in patients being operated by medium-volume surgeons, less in patients being operated by high-volume surgeons and missing in those being operated by low-volume surgeons.

Conclusions: Patients with locally advanced rectal cancers might benefit from treatment in specialized high-volume hospitals. In particular, the surgeon volume had significant influence on long-term local tumour control. The effect of neoadjuvant CRT on local tumour control may likewise depend on the surgeon volume.