Role of Allogeneic Stem Cell Transplantation in Lymphoplasmacytic Lymphoma. Analysis of 61 Cases from the European Bone Marrow Registry (EBMT).

Despite effectiveness of standard chemotherapy regimens, complete response is infrequent in Lymphoplasmacytic Lymphoma (LPL) patients and there is no cure. The role of allogeneic stem cell transplantation (ASCT) has not been explored extensively and the available data are limited. We studied retrospectively LPL patients from 47 European centres who underwent conventional (CT) and non-myeloablative (NMT) allogeneic stem cell transplantation between 1989 and 2003. Sixty-one patients (42 male) of median age at transplant of 41 years (38–57), underwent allogeneic transplantation for LPL. Thirty-two patients were treated with CT and 29 NMT. Thirteen patients received 1, 25 received 2 and 23 more than 2 previous treatment lines. Seven patients were in CR1, 20 in CR2, 19 in PR and 15 with PD. Conditioning used was a combination of TBI and cyclophosphamide or busulfan for the CT and Fludarabine based regimens for the NMT. Twenty-six NMT and 25 CT patients received stem cells from an HLA-identical sibling, while 3 NMT and 7 CT from a matched unrelated donor. For GVHD prophylaxis or treatment cyclosporin A, Methotrexate, ATG, MoAB, T-cell depletion were used. Nine NMT patients received donor lymphocyte infusion for either residual disease or mixed chimera. Median follow up is 7 months (1 to 168). Twenty-nine patients developed a-GVHD (47.5%) [Grade I-II (n=25), Grade III-IV (n=4)] with no statistically significant difference between the 2 groups. Eleven CT patients (34.4%) and 10 NMT (34.5%) patients died from regimen toxicity. Non-relapse mortality was the same for both groups. One CT and 2 NMT patients relapsed and died from disease progression. The progression free survival (PFS) is 51%, at 1 and 41% at 3 years for the entire group and comparison between CT and NMT has not shown a statistical significant difference. Relapse rate at 2 years for CT and NMT is 23% and 34% respectively. Overall survival for CT is 60% at 1 and 55% at 3 years and is similar in the two groups. In conclusion allogeneic stem cell transplantation is safe with moderate non-relapse toxicity and good overall response in this group of advanced and multitreated LPL patients.