High dose chemotherapy with autologous stem cell transplant for patients with transformed B-cell non-Hodgkin lymphoma in the rituximab era.

High dose chemotherapy with autologous stem cell transplant (HD-ASCT) is a recommended procedure for patients with transformed indolent B-cell lymphoma from the pre-rituximab era. In this retrospective single-center study, we present our experience with HD-ASCT in patients with histologically verified transformed indolent B-cell lymphoma in the rituximab era. Forty-two patients were included, of whom 28 with chemosensitive disease proceeded to HD-ASCT. Twenty patients (71%) achieved a complete response (CR) and five (18%) a partial response (PR) after HD-ASCT. With a median observation time of 49 months for the survivors, the median progression-free survival (PFS) and overall survival (OS) for patients with HD-ASCT were 39 months and 57 months, respectively. Patients who were rituximab-naive at transformation had a significantly better OS compared to patients previously treated with rituximab, both in the whole patient cohort and among the HD-ASCT-treated patients (p = 0.036 and p = 0.039, respectively). Furthermore, male sex influenced survival negatively, whereas time from diagnosis to transformation was positively associated with survival, both with borderline significance, in HD-ASCT-treated patients. In conclusion, HD-ASCT remains an effective treatment for transformed indolent lymphomas in the rituximab era.