Hematopoietic Stem Cell Transplantation (HSCT) in Waldenström Macroglobulinemia (Wm), Update of the French Experience in 54 Cases.

Introduction: HSCT has been developed in few Wm cases and is nowadays challenged by other innovative approaches. However, high dose therapy followed by autologous HSCT (HD-auto) produces high response rate and some long term responses while allogeneic HSCT performed after either myeloablative (MA-allo) or reduced intensity conditioning (RIC-allo) regimens may be cure of Wm (Dreger 1998, Tournilhac 2003, Maloney 2006). Methods: We updated and extended our retrospective experience on 32 HD-auto, 11 MA-allo and 11-RIC-allo performed from 1990 to 2006 in 51 patients from 18 institutions. A MA-allo and a RIC-allo were performed in 1 and 2 cases respectively following relapse after a 1st HD-auto. Results: Data are presented in the table. HD-auto MA-allo RIC-allo Nb 32 11 11 Median age at transplant 56 46 56 Interval: diagnosis-transplant 38 50 74 Chemoresistance at transplant 25% 36% 55% Conditioning regimen BEAM (13), TBI/melphalan (9), TBI/endoxan (7), other (3) TBI/endoxan (9), other (2) TBI/fluda (10), other (1) Donor Sibling (9), unrelated (2) Sibling (8), unrelated (2), cord blood (1) Median follow up (m) 45 (3–121) 68 (3–132) 22(2–60) Relapse 18 (56%) 4 (36%) 0 Transplant related mortality 12,5% (one 2th cancer) 36% 27% (one 2th cancer) overall survival (1;3;5y) 87%, 77%, 58% 64%, 54%, 54% 82%, 68%, 68% Event free survival (5y) 25% 48% 68% Acute GVHD developed following 9 MA-allo [Grade III-IV (n=1)] and 8 RIC-allo [Grade III-IV (n=1)]. Chronic GVHD developed following 7 MA-allo [limited (n=5), extensive (n=2)] and 5 RIC-allo [limited (n=2), extensive (n=3)]. Conclusion: We confirm that autologous HSCT achieves some long term responses even in heavily pretreated patients. Allogeneic HSCT induces very long term disease control and may cure WM. Specially, the RIC-allo gives impressive results on disease control in a set of older patients, with refractory disease, mostly heavily pretreated.