High-Dose Therapy Followed by Autologous HSCT in Patients with Multiple Myeloma. Results of a Retrospective Multicenter Analysis Conducted by The Polish Myeloma Group.

In recent years high-dose therapy with autoHSCT has become the treatment of choice for eligible patients with multiple myeloma. This disease is now one of the most common indications for autotransplantation. The aim of this study was the clinical assessment of patients who underwent autotransplantation of progenitor cells and an analysis of the results of conducted treatment. The Polish Myeloma Group collected results of auto HSCT from 12 transplantology centres in Poland conducted between 1995 and 2006. We analyzed retrospectively the prognostic influence of pre-transplant characteristics on response and survival in 498 patients. Virtually all the patients received peripheral blood stem cell support after conditioning with melphalan (95%). We evaluated the influence of age, type of myeloma, Durie-Salmon stage, presence of renal impairment, plasma cell infiltration, albumin and b₂ microglobulin level at diagnosis, status prior to and post HSCT, time from diagnosis to HSCT on overall survival (OS) and progression-free survival (PFS) to define patients with better prognosis. 232 females and 266 males underwent auto HSCT, and these included 297 (59,6%) with IgG, 97 (19,5%) with IgA, 31 (6%) with B-J, 22 (4,4%) with non-secretory myeloma. Bone structure changes were ascertained in 355 patients (71%). Bone marrow involvement higher than 20% was found in 282 patients (56,6%) at diagnosis. A decreased level of albumin (<35g/l) was determined in 168 patients (33,7%), and b₂microglobuline level above 3,5 mg/l in 124 patients (24,9%). Transplantation of progenitor cells was conducted as consolidation of first line treatment following chemotherapy according to VAD in the majority of patients (74,7%). This number increased to 246 (49,4%) following transplantation. Double transplantation was conducted in 132 patients (26,5%). Median OS and PFS obtained were 3272 (1391–4232) and 1158 (102–3767) days respectively. CR achieved before transplantation, normal renal function, albumin level above 35g/l, b₂ mikroglobulin below 3,5mg/l and DS stage I, were associated with a longer OS and PFS (p<0,05). This retrospective, multicenter study confirms the efficacy and safety of autoHSCT in multiple myeloma patients. Additional confirmation is given of the increased rate of CR, and the significantly prolonged survival observed in complete responders. Taking the above into account the employment of new drugs, such as thalidomide or bortezomib, which allow the achievement of a higher percentage of remissions should in the future bring about an improvement of the efficacy of transplantation in multiple myeloma.