Impact of center volume on acute graft versus host disease in allogeneic stem cell transplant recipients.

Prophylactic, diagnostic, and treatment strategies for acute graft-versus-host disease (aGVHD) may vary across medical centers and physicians. We aimed to investigate the relationship between center volume and the incidence and outcomes of aGVHD. This retrospective study included 28,786 patients who underwent their first hematopoietic stem cell transplantation (HSCT) (entire cohort) and 9498 patients who developed grade II-IV aGVHD (aGVHD cohort). Data were categorized into quartiles (very low, low, high, and very high) based on the number of HSCTs the treating center performed during the study period. We assessed the incidence of aGVHD using the entire cohort and overall survival (OS) using the aGVHD cohort. Higher center volume was associated with a higher incidence of grade II-IV aGVHD than very low center volume, with an adjusted hazard ratio of 1.07-1.11. Conversely, center volume was not associated with the incidence of grade III-IV aGVHD. OS after development of aGVHD was better in the higher center volume group than the very low-volume group, with an adjusted hazard ratio of 0.81-0.89. A very low-volume center was associated with a lower incidence of grade II-IV aGVHD in patients with allogeneic HSCT and poor survival in patients with aGVHD.