[Risk factors of extramedullary relapse after allogeneic hematopoietic stem cell transplantation in patients with...

Objective: To evaluate risk factors and available treatments of extramedullary relapse (EMR) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myeloid leukemia. Methods: A total of 280 patients were retrospectively analyzed from January 2008 to December 2018 in Affiliated Cancer Hospital of Zhengzhou University. Clinical data were collected including disease patterns, pre-transplantation status, chromosome karyotype, conditioning regimen, types of donor, extramedullary disease before transplantation and graft-versus-host disease (GVHD). The log-rank test and Cox proportional hazard model were uesd for univariate analysis and multivariate analysis, respectively. Results: Twenty patients developed EMR (7.14%). The median time of EMR was 7.5 (1-123) months after allo-HSCT. The mortality of EMR was 80% (16/20). Univariate analysis identified disease patterns, second complete remission (CR2) or progressive disease before transplantation, extramedullary disease, abnormal karyotype and conditioning regimen without total body radiation as significant factors correlated to EMR (P<0.05). Multi-variable analysis revealed that CR2 or progressive disease (RR=3.468,95%CI 2.189-7.786), abnormal karyotype (RR=1.494,95%CI 1.020-2.189) and extramedullary disease before transplantation (RR=8.627,95%CI 3.921-18.452) were independent risk factors of EMR. Conclusions: The clinical outcome of EMR after allo-HSCT is poor.It is crucial to comprehensively assess and identify EMR as early as possible.