Splenectomy before allogeneic hematopoietic cell transplantation for myelofibrosis: A French nationwide study.

The value of pretransplant splenectomy in patients with myelofibrosis (MF) is subject to debate, since the procedure may preclude subsequent allogeneic hematopoietic cell transplantation (allo-HCT). To determine the impact of pretransplant splenectomy on the incidence of allo-HCT, we conducted a comprehensive retrospective study of all patients with MF for whom an unrelated donor search had been initiated via the French bone marrow transplantation registry (RFGM) between 1 January 2008 and 1 January 2017. Additional data were collected from the patients' medical files and a database held by the French-Language Society for Bone Marrow Transplantation and Cell Therapy (SFGM-TC). We used a multistate model with four states ("RFGM registration"; "splenectomy"; "death before allo-HCT", and "allo-HCT") to evaluate the association between splenectomy and the incidence of allo-HCT. The study included 530 patients from 57 centers. With a median follow-up time of 6 years, we observed 81 splenectomies, 99 deaths before allo-HCT (90 without splenectomy and nine after), and 333 allo-HCTs (268 without splenectomy and 65 after). In a bivariable analysis, the hazard ratio [95% confidence interval (CI)] for the association of splenectomy with allo-HCT was 7.2 [5.1-10.3] in the first 4 months and 1.18 [0.69-2.03] thereafter. The hazard ratio [95% CI] for death associated with splenectomy was 1.58 [0.79-3.14]. These reassuring results suggest that splenectomy does not preclude allo-HCT in patients with MF.