Long-Term Results in Multiple Myeloma After High-Dose Melphalan and Autologous Transplantation According to Response Categories in the Era of Old Drugs

Abstract Background The aim of this study was to investigate the correlation between the long-term prognosis of multiple myeloma (MM) and the quality of response to therapy in a cohort of 173 patients treated with high-dose melphalan (HDM) and autologous transplantation in the era of old drugs. Patients and Methods A total of 173 patients with de novo MM who received a transplant between 1994 and 2010 were analyzed. VAD (vincristine, doxorubicin [Adriamycin], dexamethasone) was used as front-line regimen before auto-HPCT. The conditioning was HDM 200 mg/m 2 . Patients were evaluated for clinical response using the criteria from the European Group for Blood and Marrow Transplantation, modified to include near complete remission (nCR) and very good partial remission (VGPR). Results The response distribution after transplantation in our series was complete remission (CR) in 33 cases (19%), nearly complete remission (nCR) in 38 cases (22%), VGPR in 30 cases (17%), partial remission (PR) in 65 cases (38%), and stable disease (SD) in 7 cases (4%). Patients were followed for 48 ± 36 months. Median overall survival (OS) was not reached for the CR group. Progression-free survival (PFS) was 122 months for CR, 55 months for nCR, 56 months for VGPR, 32 months for PR, and 22 months for SD. Significant differences in PFS and OS were found between the CR and nCR groups ( P  = .003 and P  = .001, respectively), between the CR and VGPR groups ( P  = .002 and P  = .001, respectively), and between the CR and PR groups ( P  = .000 and P  = .001, respectively). Responses were clustered in 3 main categories, ie, CR, nCR + VGPR + PR, and SD. The respective 10-year PFS and OS values were 58% and 70% for CR, 15% and 18% for nCR + VGPR + PR, and 0% and 0% for SD. Conclusion The achievement of depth and prolonged response represents the most important prognostic factor. The relapse rate is low for patients in CR after 10 years of follow-up, possibly signifying a cure.