Impact of spleen size and splenectomy on outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis: A retrospective analysis by the chronic malignancies working party on behalf of European society for blood and marrow transplantation (EBMT)

Abstract

The role of spleen size and splenectomy for the prediction of post‐allogeneic hematopoietic stem cell transplant (allo‐HCT) outcome in myelofibrosis remains under debate. In EBMT registry, we identified a cohort of 1195 myelofibrosis patients transplanted between 2000‐2017 after either fludarabine‐busulfan or fludarabine‐melphalan regimens. Overall, splenectomy was performed in 202 (16.9%) patients and its use decreased over time (28.3% in 2000‐2009 vs 14.1% in 2010‐2017 period). By multivariate analysis, splenectomy was associated with less NRM (HR 0.64, 95% CI 0.44‐0.93, P = .018) but increased risk of relapse (HR 1.43, 95% CI 1.01‐2.02, P = .042), with no significant impact on OS (HR 0.86, 95% CI 0.67‐1.12, P = .274). However, in subset analysis comparing the impact of splenectomy vs specific spleen sizes, for patients with progressive disease, an improved survival was seen in splenectomised subjects compared to those patients with a palpable spleen length ≥ 15 cm (HR 0.44, 95% CI 0.28‐0.69, P < .001), caused by a significant reduction in NRM (HR 0.26, 95% CI 0.14‐0.49, P < .001), without significantly increased relapse risk (HR 1.47, 95% CI 0.87‐2.49, P = .147). Overall, despite the possible biases typical of retrospective cohorts, this study highlights the potential detrimental effect of massive splenomegaly in transplant outcome and supports the role of splenectomy for myelofibrosis patients with progressive disease and large splenomegaly.

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

“…In conclusion, our study yielded reassuring results with regard to pretransplant splenectomy; this procedure did not preclude allo-HCT in patients with MF. Together with the results by Polverelli et al 16 these suggest that pretransplant splenectomy can be safely performed and appears beneficial in patients with a massive splenomegaly,…”

“…15 In the current issue of the American Journal of Hematology, Polverelli et al showed that splenectomy was associated with a lower rate of non-relapse mortality but a higher relapse rate in MF patients, and with a better overall survival in those with a massive splenomegaly. 16 Besides, splenectomy per se can be hazardous in patients with MF because it is associated with a substantial risk of thrombosis, hemorrhage or infection. [17][18][19] Some researchers have speculated that this type of complication could delay or even preclude allo-HCT in patients for whom no other curative options exist.…”

Impact of prior JAK-inhibitor therapy with ruxolitinib on outcome after allogeneic hematopoietic stem cell transplantation for myelofibrosis: a study of the CMWP of EBMT

“…We observed a low risk of graft failure in patients who responded regarding spleen size to RUX prior to transplantation (6%) in comparison to RUX pretreated patients with no or lost spleen response prior to HSCT (15%), which highlights the role of spleen size regarding risk of graft failure in myelofibrosis patients [ 22 ]. This is further supported by 7% graft failure incidence of the non-RUX pretreated patients who had only a median spleen size of 8 cm at time of HSCT.…”

Myelofibrosis: Genetic Characteristics and the Emerging Therapeutic Landscape

“…136 Similarly favorable outcome data have also been reported in patients receiving alternative donor grafts. 141 Unresolved issues with AHSCT in MF include the role of splenectomy, [142][143][144] involved field radiotherapy, 145,146 and use of JAK2 inhibitors before and after AHSCT. [147][148][149][150][151] recent publications have addressed the issue of pre-transplant management of splenomegaly in MF, including splenectomy, splenic irradiation and use of JAK2 inhibitors.…”