Treatment Strategies and Outcomes for Patients with Peripheral T-Cell Lymphoma and Its Subtypes
Authors: Roy Arya Mariam , Pandey Yadav , Konda Manojna , Yarlagadda Naveen , Sasapu Appalanaidu 
Published: November 2020

Introduction
Peripheral T-cell lymphoma (PTCL) is diverse group of an uncommon and aggressive type of non-Hodgkin lymphoma (NHL). It generally affects people aged 60 years and above and is diagnosed slightly more often in men than in women. However, younger adults and children are also diagnosed with PTCL. Being a rare entity, the best treatment regimen has not been established for newly diagnosed patients or for relapsed/refractory patients with PTCL. In general, treatment outcomes have been poor with conventional chemotherapy regimens.
Methods
We performed a retrospective cohort study of patients with newly diagnosed and relapsed PTCL, and its subtypes, who are seen in the hematology-oncology clinic at the University of Arkansas for Medical Sciences from July 2014 to December 2019. The demographics of the study population, the frontline and second-line treatment strategies for all the subtypes and the response to the treatment were studied. Also, the role of high dose chemotherapy followed by autologous stem cell transplantation (HDT-ASCT) in the overall survival (OS) and progression-free survival (PFS) is analyzed.
Results
Out of the 48 patients, 45.8% (n=22) patients had PTCL not otherwise specified (PTCL NOS) type, 29% (n=14) had Anaplastic large cell lymphoma ALK-negative subtype, 4.2 % (n=2) had Anaplastic large cell lymphoma ALK-positive subtype, Angioimmunoblastic T-cell lymphoma, Extra nodal NK/T cell lymphoma, Enteropathy associated T- cell lymphoma each. The mean age of diagnosis was 58 ± 2. Males were affected more when compared to females (66.6% vs 33.3%). Also, Caucasians were more affected than African Americans (73% vs 25%). The mortality of PTCL was found to be 40%. After frontline treatment, complete response (CR) was observed in 43.7% (n= 21) patients, partial response (PR) was observed in 18.7% (n= 9) patients, stable disease (SD) was seen in 4% (n=2), progression of disease (PD) was observed in 12.5% (n= 6) patients. Stem cell transplant (HDT-ASCT) was done for 28% (n=13) of patients who achieved CR after frontline chemotherapy (CR1). Relapse was observed in 60% of patients. Patients with stage III and IV on the initial diagnosis had a higher chance of relapse or refractory disease. After the second-line treatment, out of 20 patients, 9 patients had CR, 5 had PR, 5 patients had PD, 1 patient had SD. CR was observed in 7 patients with either brentuximab vedotin alone or brentuximab vedotin with combination chemotherapy as second-line treatment. The OS and PFS were found to be higher in patients who received HDT-ASCT after CR1.
Conclusion
PTCL has a high risk of relapse and there are no uniform guidelines for the treatment of PTCL in relapsed or refractory setting. The currently available second line treatment options have shown modest response rates. Our study has shown that brentuximab vedotin, when used alone or in combination, showed better response rate in the relapsed setting. Also, stem cell transplant improved the overall survival and progression-free survival in patients with PTCL after frontline chemotherapy.

Disclosures
No relevant conflicts of interest to declare.