OBJECTIVETo explore the effect of treatment option on the response and outcomes in multiple myeloma (MM) patients suitable for autologous hematopoietic stem cell transplantation (auto-HSCT).

METHODSA total of 71 newly-diagnosed MM patients less than 65 years admitted to RuiJin Hospital from June 2005 to December 2009 were analyzed retrospectively. Among them, 21 received auto-HSCT (HSCT group) with standard conditioning of melphalan 200 mg/m(2), 30 received conventional chemotherapy (conventional group) and 20 received Bortezomib-based therapy (Bortezomib group). The responses and outcomes of different treatments were analyzed.

RESULTSThe median follow-up duration for all patients was 18 (1 - 58) months with estimated 3-year overall survival (3-yr OS) of (79.8 ± 6.3)% and progression-free survival (3-yr PFS) of (54.8 ± 9.0)%. Thirty-four patients achieved complete remission (CR) or very good partial remission (VGPR) on induction therapy, which were 80% for the Bortezomib group, 33.3% for the conventional group and 38.3% for the HSCT group. After auto-HSCT the CR + VGPR rate was increased to 76.1% for the HSCT group. Overall, the 3-yr PFS was (26.3 ± 13.8)% (median 21 months), (40.5 ± 20.1)% (median 25 months) and (93.8 ± 6.1)%(median not reached, P = 0.025) for conventional, Bortezomib and HSCT groups respectively. Univariate analysis demonstrated that CR/VGPR after induction (P = 0.020), best response of CR/VGPR (P < 0.01), autoHSCT (P = 0.002) and maintenance therapy after CR/VGPR (P = 0.0005) were associated with improved PFS and that CR/VGPR after induction (P = 0.009), best response with CR/VGPR (P < 0.01), maintenance therapy for any patients (P = 0.035) and maintenance therapy for patients with CR/VGPR (P = 0.031) were associated with OS. In multivariate analysis, only auto-HSCT (P = 0.039) and best response of CR/VGPR (P = 0.009) were independent prognostic factors for PFS and the best response of CR/VGPR was the only independent prognostic factor for OS (P = 0.005). The estimated 3-yr OS was (62.4 ± 13.7)%, (94.1 ± 5.7)% and (87.9 ± 8.3)% respectively for 3 groups.

CONCLUSIONSFor newly-diagnosed MM younger than 65 are suitable for auto-HSCT, the best response of CR/VGPR was associated with OS and PFS. Auto-HSCT is also important prognostic factor for PFS. Induction therapy with Bortezomib can achieve rapid CR/VGPR while auto-HSCT as a crucial consolidation therapy and maintenance therapy maybe also important for improvement of long-term outcome.