Different Outcome for Angioimmunoblastic T-Cell Lymphoma (AIL) and Peripheral T-Cell Lymphoma Unspecified (PTCL-U) Following Upfront Autologous Stem Cell Transplantation.

Abstract

Introduction: Peripheral T-cell lymphomas (PTCL) are rare diseases and optimal treatment strategies still remain to be defined. With the exception of the ALK-positive anaplastic large cell lymphoma (ALCL) that shows a favourable outcome following conventional chemotherapy, PTCL are known for their poorer prognosis compared to aggressive B-cell lymphomas. However, the impact of the different PTCL-subtypes on treatment outcome has not been clearly demonstrated in prospective studies. PTCL unspecified (PTCL-U) and angioimmunoblastic T-cell lymphoma (AIL) represent the most common subtypes of PTCL in Western countries, accounting for approximately 70% of PTCL. We therefore analysed the data of our study on myeloablative radiochemotherapy followed by autologous stem cell transplantation (ASCT) in primary diagnosed PTCL with regard to the main histologic subtypes.Material and Methods: From 06/00 to 06/06 92 patients with confirmed diagnosis of PTCL entered the study. Primary cutaneous PTCL and ALK+ ALCL were excluded from the trial. Main subtypes were PTCL-U (n= 37) and AIL (n= 28) accounting for 65 of the 92 patients (71%). 0f these patients 53 (PTCL, n= 31; AIL, n= 22) were evaluable for the analysis (82%).Results: Median age was 50 years in the PTCL-U and 47.5 years in the AIL group, respectively. The International Prognostic Index (IPI) did not differ in both groups. In the PTCL-U and the AIL group a low/intermediate-low risk was found in 35% and 36%, respectively and a high/intermediate-high risk in 65% and 64%, respectively. There were slightly more patients in stage IV in the AIL group compared to the PTCL-U group (64% versus 53%). In addition, more patients in the AIL group complained of B-symptoms and had bone marrow involvement compared to the PTCL-U group (86% versus 66% and 48% versus 39%, respectively). However, in an intent-to treat analysis only 58% in the PTCL-U group compared to 82% in the AIL group underwent ASCT mainly due to a higher rate of patients with progressive disease in the PTCL-U group. The median overall survival (OS) was 11 months in the PTCL-NOS and 20 months in the AIL group. Regarding only patients undergoing ASCT, the median OS was 13.5 months in the PTCL-U and 25.5 months in the AIL group.Conclusion: Our analysis suggests that patients with AIL, although showing a slightly more unfavourable risk profile at diagnosis, benefit more from upfront autotransplantation than patients with PTCL-U in our study.