Allogeneic hematopoietic stem cell transplantation for advanced mycosis fungoides and Sezary syndrome. An updated experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation

Background Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a potentially curative treatment option in advanced-stage mycosis fungoides (MF) and Sezary syndrome (SS). This study presents an updated analysis of the initial experience of the Lymphoma Working Party of the European Society for Blood and Marrow Transplantation (EBMT) describing the outcomes after allo-HSCT for MF and SS, with special emphasis on the impact of the use of unrelated donors (URD). Methods and patients Eligible for this study were patients with advanced-stage MF or SS who underwent a first allo-HSCT from matched HLA-identical related or URD between January/1997 and December/2011. Sixty patients have been previously reported. Results 113 patients were included [77 MF (68%)]; 61 (54%) were in complete or partial remission, 86 (76%) received reduced-intensity protocols and 44 (39%) an URD allo-HSCT. With a median follow up for surviving patients of 73 months, allo-HSCT resulted in an estimated overall survival (OS) of 38% at 5 years, and a progression-free survival (PFS) of 26% at 5 years. Multivariate analysis demonstrated that advanced-phase disease (complete remission/partial remission >3, primary refractory or relapse/progression in patients that had received 3 or more lines of systemic treatment prior to transplant or the number of treatment lines was not known), a short interval between diagnosis and transplant (<18 months) were independent adverse prognostic factors for PFS; advanced-phase disease and the use of URDs were independent adverse prognostic factors for OS. Conclusions This extended series supports that allo-HSCT is able to effectively rescue over one third of the population of patients with advanced-stage MF/SS. High relapse rate is still the major cause of failure and needs to be improved with better strategies before and after transplant. The negative impact of URD is a matter of concern and needs to be further elucidated in future studies.