Autologous Stem Cell Transplantation In Mantle Cell Lymphoma: The Experience of the French SFGM-TC Group
Authors: Touzeau Cyrille , Delarue Richard , Leux Christophe , Roussel Murielle , Bouabdallah Krimo , Tournilhac Olivier , Cartron Guillaume , Compain Laetitia , Gyan Emmanuel , Thieblemont Catherine , Casasnovas Olivier , Moles Marie-Pierre , Blaise Didier , Franck Morschhauser , Peterlin Pierre , Mohty Mohamad , Milpied Noel , Le Gouill Steven 
Published: October 2019

Abstract
Abstract 2392
Mantle cell lymphoma (MCL) is an aggressive and rare B-cell lymphoma entity representing around 5–8% of non-Hodgkin's lymphomas (NHLs) in adults. The hallmark of MCL is the t(11;14) which promotes cycline D1 overexpression. In France as in several European countries, autologous stem cell transplantation (ASCT) is the standard care for young MCL patients. Some recent prospective trials have suggested that ASCT could be a curable treatment for a subgroup of MCL patients. However, additional studies with long term follow-up (FU) are needed in order to confirm or not this statement. The present study is a retrospective analysis conducted on behalf of the Société Française de Greffe de Moëlle et de Thérapie Cellulaire (SFGM-TC). We aimed to investigate the outcome of MCL patients who underwent ASCT and parameters that influence both OS and EFS. All transplanted MCL patients recorded in the SFGM-TC database were eligible for the present study. Participating centers were asked to confirm the MCL diagnosis, to update biological and clinical parameters and FU. Five hundred files have been analyzed to date. The number of ASCT for MCL patients increased during the last years with 144 patients transplanted from 2003 to 2005 as compared to only 149 patients prior 2003. Since 2003, around 50 MCL patients per year undergo ASCT in France. Patients'characteristics: sex gender was male in 79.2%. At time of diagnosis, 134 patients (26.8%) were <50 years old and 128 (25.6%) were > 59 years old. More than half of the patients had a stage IV disease. The majority of these patients underwent ASCT upfront (78.8%; n=394). The conditioning regimens were BEAM (32%), TBI/Aracytin/Melphalan (TAM) (10.6%), TBI/melphalan (10.2%) or TBI/cyclophosphamide (13.2%) (data missing=156). The use of TBI for transplant conditioning decreased from 56% before 2003 to 39% after. Regarding patient outcomes, the medium FU for living patients is 34.4 months. The median EFS rate calculated after ASCT is 49.7 months and 191 experienced relapse or progression. The 3- and 5- year EFS estimates are 63.3% and 44.8%, respectively. One hundred thirty patients died and the median OS is 99 months. The 3- and 5- year OS estimates are 79.5% and 68.2%, respectively. Both EFS and OS curves show no plateau and late relapses have been reported more than 7 years after ASCT. Among patients with at least one year of FU (n=380), a secondary malignancies is reported in 27 cases (7%). In the group of patients who underwent ASCT upfront, the median EFS and OS duration are 58.8 and 114 months, respectively. For these patients (n=394), a blastic variant (p=3.10-5; p=.01), a Ki67 staining >30 (p=.01; p=.01), ECOG PS >2 (p=5.10-5; p=.01) and a high-risk MIPI (p=.003; p=.003) are adverse parameters that impact both EFS and OS, respectively. High-risk age-adjusted IPI have also an adverse prognostic impact on EFS (p=.001). At relapse, 25 patients underwent allogeneic stem cell transplantation and 19 (76%) obtained at least a partial response. This large retrospective analysis is ongoing and still represents one of the most important series of transplant MCL patients.

Disclosures:
No relevant conflicts of interest to declare.