Purpose: To assess the outcome of high–dose therapy with autologous stem cell support (HDT) in patients with transformed follicular lymphoma compared to patients with de novo aggressive B-cell lymphoma, in a retrospective analysis of patients treated at two Swedish university hospitals.
Patients and Methods: 117 patients, mean age 48 years (21-65), 79 with de novo aggressive B-cell lymphoma and 38 with transformed follicular lymphoma, were treated with high-dose-therapy (HDT) as consolidation. Thirteen patients with transformed follicular lymphoma had been treated with a single alkylating agent and 25 were chemonaive at transformation. After transformation, nine patients had HDT as part of first line aggressive therapy, and a further eight failed to obtain CR and had HDT upfront. Twenty-one patients received more than one treatment regimen before HDT. In the de novo aggressive lymphoma group five patients with high risk criteria, and 16 patients who failed to obtain CR, received HDT upfront (CR1), Fifty-eight patients received more than one regimen before HDT because of relapse. Rituximab was given as a single dose to five patients for in vivo purging of the stem cell graft.
Results: With a median follow up of 11.5 years (8-20), event free survival (EFS) and overall survival (OS) were 35% and 44% respectively. When comparing the two groups, the ten- year EFS rates were 27% in the de novo group and 55% in the transformed group and the ten-year OS was 33 % and 67% respectively. Treatment related mortality was acceptable with 4% early and 3.5% late mortality. In a multivariate analysis, “transformed vs de novo aggressive” histopathology was the only factor significantly related to outcome.
Conclusion: Both EFS and OS were much better in patients with transformed follicular lymphoma compared to patients with de novo aggressive B-cell lymphoma Although the introduction of rituximab certainly has improved the outcome in both groups, HDT should still be considered as a salvage strategy not only in cases of de novo aggressive B-cell lymphoma and especially in transformed follicular lymphoma relapsing after first line treatment..