Allogeneic stem cell transplantation in mature T-cell and NK/T neoplasias. A registry study from Spanish GETH/GELTAMO centers

ABSTRACT Background Despite advances in understanding the biology of mature T and NK/T-cell neoplasia, current therapies, even the most innovative ones, are still far from ensuring its cure. The only treatment to date that has been shown to control aggressive T neoplasms in the long term is allogeneic transplantation (alloSCT). Objective We aim to report the results of alloSCT for advanced mature T and NK/T neoplasias performed in centers from our national GELTAMO/GETH over the last 25 years. As a secondary objective, we analyzed the results of alloSCT from haploidentical donors. Study design We performed a retrospective analysis of all patients that received an alloSCT in Spanish centers (n= 201) from September 1995 to August 2018 Results The 2-year overall (OS) and disease free survival (DFS) were 65.5% and 58.2%, respectively. The univariate for OS and DFS showed statistically different hazard ratios for conditioning intensity, response pre alloSCT, comorbidity index, donor/receptor CMV status and ECOG pre-alloSCT but only a better ECOG pre-alloSCT remained significant in the multivariate analysis. There was an increased incidence of relapse in those patients who did not develop chronic graft versus host disease (GvHD) and an increased risk of death in those developing moderate-severe acute GvHD. The 1-year non-relapse mortality was 21.9 % and was mainly due to GvHD (30%) and bacterial infections (17%). When comparing unrelated donor with haploidentical donor we found similar results in terms of OS and DFS. There was however a reduction of acute GvHD in haploidentical group (p=0.04) and trend to a reduction of cGvHD. Conclusion(s) : In resume, alloSCT is the only curative option for the majority of aggressive T-cell neoplasias. Haploidentical donors offers similar results to related donors in terms of survival with a reduction of acute GvHD.