The Role of Autologous Stem Cell Transplantation (ASCT) in Patients with Advanced Waldenström’s Macroglobulinemia.

Waldenström’s macroglobulinaemia (WM) is a relatively rare disorder that primarily affects elderly patients. Conventional therapies for symptomatic WM result in response rates of up to 70%. However, complete responses are rare and the disease remains incurable. Due to the indolent nature of the disease and the older age of patients the role of autologous stem cell transplantation (ASCT) in the treatment of patients with WM has not been analyzed in large series. In this retrospective multicenter study we report the outcome of 201 WM patients (132 male, 69 female), who underwent ASCT between 1992 and 2005. The median age at transplant was 53 years (22–73) and the median time from diagnosis to transplant was 18 months (3–239). Forty patients (20%) were in 1^st maximum response (MR1), 24 (12%) in ≥MR2, 83 (41%) in PR1, 27 (13%) in ≥PR2 and 27(14%) were primary refractory to treatment. Conditioning regimens were BEAM (44%), TBI/Cyclophosphamide or Melphalan (28%), Melphalan (14%), BuCy (2%) and others (12%). The source of stem cells was PB in 188, BM in 10, and both in 3 patients. All patients but 3 had successful engraftment. With a median follow-up of 26 months (5–163), 112 (56%) patients are alive and free of disease, 73 (36%) patients have relapsed after a median of 14 months (1–110) post ASCT. Fifty-two patients died, 36(18%) from disease progression and 16(8%) from treatment toxicity. Non- relapse mortality was 6% at 1 year. The actuarial OS was 86% at 1 year, 75% at 3 years, and 61% at 5 years. The probability of relapse was 20% at 1 year, 38% at 3 years and 55% at 5 years with an estimated PFS of 74%, 54% and 33% at 1, 3, and 5 years respectively. Multivariate analysis revealed that, chemosensitive disease at the time of ASCT was the most important factor for NRM (p<0.001), relapse rate (p<0.01), PFS (p<0.001) and OS (p<0.001). In conclusion, this study suggests that ASCT is a safe procedure in patients with WM and that a significant proportion of heavily pre-treated patients with this disorder can respond to the procedure and achieve prolonged PFS.