Allogeneic hematopoietic cell transplantation for patients with mycosis fungoides and Sézary syndrome: a retrospective analysis of the Lymphoma Working Party of the European Group for Blood and Marrow Transplantation.

Purpose: To analyze the outcome of allogeneic transplantation for mycosis fungoides and Sézary syndrome (MF/SS) in terms of nonrelapse mortality (NRM), relapse/progression (REL), progression-free survival (PFS), and overall survival (OS) and to identify factors associated with the outcome.
Patient and Methods: Sixty patients with MF (n = 36) and SS (n = 24) who received a first allogeneic hematopoietic cell transplantation (HCT) from a matched related (mRD; n = 45) or unrelated donor (mUD; n = 15) between 1997 and 2007 and who were registered in the European Group for Blood and Marrow Transplantation database were analyzed: 37 men and 23 women, median age 46.5 years (range, 22 to 66 years). Forty-four patients had TNM stage IV, and 40 patients were at advanced phase at transplantation. Forty-four patients received reduced-intensity conditioning (RIC) regimens, and 25 underwent T-cell depletion (TCD).
Results: Allogeneic transplantation in MF/SS offers an estimated OS of 66% at 1 year and 54% at 3 years, primarily driven by donor type, disease phase, and type of conditioning. RIC decreased NRM (relative risk [RR] = 4.7; P = .008) without increasing REL, leading to a higher OS (RR = 2.8; P = .03). Advanced-phase disease increases REL (RR = 3.0; P = .03) and reduces PFS (RR = 4.4; P = .002) and OS (RR = 3.5; P = .023). Recipients of mRD allogeneic HCT had better PFS (RR = 2.7; P = .006) and OS (RR = 4.0; P = .001) than their mUD counterparts. The risk of REL increases with TCD (RR = 3.2; P = .005). Some patients who experience relapse can successfully undergo rescue treatment with donor lymphocyte infusions.
Conclusion: Allogeneic transplantation is a valid therapeutic alternative for high-risk patients with advanced-stage MF/SS. Our data also suggest the existence of a clinically relevant graft-versus-lymphoma effect in MF/SS.