Long-Term Follow-Up of Autologous Stem Cell Transplantation in Patients with Diffuse Mantle Cell Lymphoma in First Disease Remission: The Prognostic Value of β₂-Microglobulin and the Tumor Score

BACKGROUND. The current study was conducted to analyze the long-term results of autologous stem cell transplantation (ASCT) in patients with diffuse mantle cell lymphoma (MCL) in first disease remission. METHODS. Thirty-three patients were treated. Thirty-one patients had Ann Arbor Stage III or Stage IV disease. The hyper-CVAD regimen (hyperfractionated intense-dose cyclophosphamide, vincristine, continuous intravenous infusion of doxorubicin, and dexamethasone, alternating with high doses of cytarabine and methotrexate plus leucovorin rescue) was used for cytoreduction before ASCT. Patients were consolidated with high-dose cyclophosphamide (120 mg/kg), total body irradiation, and ASCT. RESULTS. At a median follow-up of 49 months, the overall survival and disease-free-survival rates at 5 years were estimated to be 77% and 43%, respectively. Patients whose M. D. Anderson Lymphoma Tumor Score (TS) was ≤ 1 at the time of diagnosis or transplantation experienced longer disease-free survival compared with those whose TS was > 1 (P = 0.02). A β₂microglobulin (β₂m)level ≤ 3 mg/L at the time of diagnosis or transplantation was also found to be strongly predictive of longer survival (5-year survival rate of 100% vs. 22% in patients with a β₂m level > 3 mg/L) (P = 0.0001). CONCLUSIONS. ASCT may prolong the overall survival in a subset of patients with MCL. This improvement has been observed for the most part in patients with low β₂m levels (≤ 3 mg/L) and TS (≤ 1). Randomized trials are required to fully assess the benefits of this strategy.