Long Term Results of Autologous Hematopoietic Cell Transplantation (AHCT) for Peripheral T Cell Lymphoma: The Stanford Experience.
Authors: Chen Andy I. , McMillan Alex , Negrin Robert S. , Horning Sandra J. , Laport Ginna G. 
Published: April 2020

Abstract
The peripheral T cell lymphomas (PTCL) are uncommon malignancies that typically carry a worse prognosis than the B cell non-Hodgkins lymphomas. There is no uniform standard therapy for PTCL, and AHCT is often offered at relapse or as consolidation in first remission due to the inherently poor prognoses. We conducted a retrospective review of patients who underwent AHCT for PTCL from 1989 to 2006 at Stanford, excluding mycosis fungoides and lymphoblastic lymphoma. Fifty-eight cases were identified: systemic anaplastic large cell (ALCL, n=18), PTCL unspecified (NOS, n=17), angioimmunoblastic (AITL, n=9), nasal type extranodal NK/T (nNK/T, n=7), primary cutaneous anaplastic large cell (n=5), hepatosplenic (n=2), and adult T cell lymphoma/leukemia (n=1). The median age at AHCT was 45 years (range 18–73), and 57% were male. The graft source was mobilized peripheral blood HC in 86% and bone marrow in 14%. The graft was T cell purged in 86% of cases. The conditioning regimen was high dose cyclophosphamide, carmustine, and etoposide in 83% of cases with the rest receiving total body irradiation, carmustine, and etoposide. Fifteen patients were transplanted in first complete or partial response (CR/PR1); 32 in second or beyond CR or PR (CR/PR2+); and 11 with primary refractory disease (REF). The PTCL subtypes transplanted in CR1 (n=12) and PR1 (n=3) included nNK/T (5), AITL (4), NOS (2), hepatosplenic (2), and ALCL (2). Multiple regimens were required to achieve first response in 5 patients. Only one ALK+ (anaplastic lymphoma kinase) ALCL pt was transplanted in CR/PR1 and required 3 induction regimens. The median follow up was 5 years (yr) (range 1–12). For all subjects, five yr overall survival (OS) was 49% and 5 yr progression free survival (PFS) was 24%. Disease status at AHCT had a strong impact on PFS (p=.004) and OS (p=0.06). Five yr PFS was 51%, 17%, and 0%, respectively, and the PFS curve appeared to plateau at 5 yrs. Corresponding OS at 5 yrs for the CR/PR1, CR/PR2+, and REF patients were 76%, 41%, and 36%, respectively. The number of prior regimens and achievement of CR at day +90 post AHCT were also significant factors for PFS by univariate analysis. Age, bone marrow involvement, B symptoms, stage, and histology were not significant for PFS or OS. By multivariate analysis, CR at day +90 remained a highly significant factor for both PFS and OS (p&lt;0.0001 and p=0.0025, respectively). Only 1 patient died from treatment related mortality (&lt;2%). Of interest, 8 patients who progressed after AHCT had a stable CR to subsequent salvage therapy or allogeneic transplant. In summary, about half of PTCL transplanted in CR/PR1 are progression free at 5 yrs, but CR/PR2+ and REF patients fared poorly. CR status at day +90 after AHCT was also a robust predictor for PFS and OS. Based on these results, AHCT may benefit PTCL patients who are consolidated in first remission and deserves further study. In contrast, those with relapsed or refractory disease experienced minimal benefit, and thus novel strategies are especially needed for this group of patients.