Background: Myeloablative radio-chemotherapy followed by autologous stem cell transplantation (ASCT) significantly prolongs remission duration as compared to interferon alpha maintenance after conventional chemotherapy induction and is a well established treatment option in younger high risk patients with indolent lymphoma. This randomized trial compared the rate of successful stem cell mobilization after initial therapy with either MCP or CHOP in younger patients (< 60 years).
Methods: Previously untreated patients with advanced stage indolent lymphoma were randomly assigned to 6 cycles of CHOP or MCP for remission induction. Patients <60 years of age who were subsequently assigned to ASCT received one additional cycle of Dexa-BEAM (dexamethasone, BCNU, etoposide, cytarabine, melphalan) for stem cell mobilization. A minimum of 2x 2.0x106/kg bw CD34+ cells (including back-up) was estimated as appropriate for ASCT. Stem cells were collected and cryopreserved without any purging procedure.
Results: According to initial randomization, 45 of 79 patients assigned to ASCT had been treated with CHOP and 34 patients with MCP. 58 (73%) had follicular lymphoma, 13 (16%) mantle cell lymphoma and 8 (10%) lymphoplasmacytic lymphoma. Dexa-BEAM was well tolerated in all patients with a moderate rate of severe infections (13%) or other complications. After CHOP induction, stem cell collection was successfully performed in 42 of 45% cases (93%, 95% CI 82% to 99%). In contrast, stem cell collection was successful in only 15 of 34 patients after MCP chemotherapy (44%, 95% CI: 27% to 62%) (p=0.0003).
Conclusions: Initial therapy with MCP significantly impairs the ability to collect stem cells and should be avoided in first line therapy of patients who may qualify for myeloablative consolidation followed by ASCT