Moderate increase of secondary hematologic malignancies after myeloablative radiochemotherapy and autologous stem-cell transplantation in patients with indolent lymphoma: results of a prospective randomized trial of the German Low Grade Lymphoma Study Group.

PURPOSE: An increased risk of therapy-related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML) after high-dose therapy and autologous stem-cell transplantation (ASCT) for malignant lymphoma has been described by several studies, reporting a highly variable incidence ranging from 1% to 12%. To assess this risk more precisely, the German Low Grade Lymphoma Study Group investigated the incidence of t-MDS/t-AML after ASCT on the basis of a randomized comparison of ASCT versus interferon alfa (IFN-alpha) maintenance in indolent lymphoma. PATIENTS AND METHODS: Between 1996 and 2002, 440 patients with indolent lymphoma were randomly assigned after a cyclophosphamide, doxorubicin, vincristine, and prednisone-like induction therapy regimen to myeloablative radiochemotherapy followed by ASCT or IFN-alpha. The incidence of secondary hematologic malignancies was determined by standardized follow-up of all study patients. Bone marrow samples from patients with proven or suspected t-MDS/t-AML were centrally reviewed. RESULTS: After a median follow-up of 44 months, 431 patients were assessable. Five of 195 patients developed a secondary hematologic malignancy after ASCT. Two of these patients developed a secondary AML. Accordingly, the estimated 5-year risk for secondary hematologic neoplasias after ASCT was 3.8%. In contrast, in the IFN-alpha arm, the 5-year risk of hematologic neoplasias was 0.0% (P = .0248). CONCLUSION: The data of this randomized trial demonstrate an increased risk of secondary hematologic malignancies after myeloablative radiochemotherapy and ASCT compared with conventional chemotherapy. However, as ASCT significantly improves progression-free survival, it is currently not evident to what extent the higher rate of t-MDS/t-AML will diminish the benefit of ASCT in indolent lymphoma.

Myeloablative radiochemotherapy followed by autologous stem cell transplantation in first remission prolongs progression-free survival in follicular lymphoma: results of a prospective, randomized trial of the German Low-Grade Lymphoma Study Group.

Conventional chemotherapy has failed to substantially prolong survival for patients with advanced follicular lymphoma. To improve outcomes, the German Low-Grade Lymphoma Study Group (GLSG) initiated a randomized trial to compare the effect of potentially curative myeloablative radiochemotherapy followed by autologous stem cell transplantation (ASCT) with interferon-alpha (IFN-alpha) maintenance therapy in first remission. Three hundred seven patients (younger than 60 years) with follicular lymphoma were recruited into the trial from 130 institutions. After 2 cycles of cyclophosphamide-doxorubicin-vincristine-prednisone (CHOP) or mitoxantrone-chlorambucil-prednisone (MCP) induction chemotherapy, patients were randomly assigned to either the ASCT or the IFN-alpha group. The respective therapy was started when patients achieved complete or partial remission after induction chemotherapy. Two hundred forty patients with follicular lymphoma are evaluable for the comparison of ASCT and IFN-alpha. In patients who underwent ASCT, the 5-year progression-free survival (PFS) rate was 64.7%, and in the IFN-alpha arm it was 33.3% (P < .0001). As expected, acute toxicity was higher in the ASCT group, but early mortality was below 2.5% in both study arms. In this randomized, multicenter trial, high-dose radiochemotherapy followed by ASCT significantly improved PFS compared with IFN-alpha in patients with follicular lymphoma when applied as consolidation in first remission. Longer follow-up is necessary to determine the effect of ASCT on overall survival.