The role of hematopoietic stem cell transplantation in peripheral T-cell lymphoma not otherwise specified

Abstract

Abstract Introduction Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) is the most common subtype of peripheral T-cell lymphoma. It is characterized by aggressive clinical behavior and poor prognosis and treatment often includes chemotherapy, but the benefit of hematopoietic stem cell transplantation (HSCT) remains an area of ongoing investigation. Using the National Cancer Database, we analyzed the impact of HSCT on survival in a large cohort of patients with PTCL-NOS. Materials and Methods We queried the National Cancer Database (NCDB) for patients aged 18 or older diagnosed with PTCL-NOS between 2004 and 2019. Patients who lost to follow-up were excluded. We analyzed the impact of HSCT on overall survival (OS) using Kaplan-Meier estimates and multivariate Cox regression to identify factors associated with OS. Results A total of 14,301 patients with PTCL-NOS were included in this analysis. Among them, 60.1% were male, 65.7% were Caucasian, 17.1% were black and 7.4% were Hispanic. Early-stage disease (stage I or II) was present in 24.1%, while 49.3% patients had advanced-stage disease (stage III or IV). The median age at diagnosis was 65 years (range 18-90, 23.6% were above age 75), and the median overall survival (mOS) was 15.3 months (95%CI 14.6-16), with a median follow-up of 82.8 months (95%CI 80.4-85.2). Regarding first-line treatment, 11.7% received radiation therapy, 68.9% received chemotherapy, and 6.6% underwent HSCT. The percentage of patients receiving HSCT increased from 3.3% in 2004 to 9.9% in 2019, tripling over the 16-year period. Transplant utilization varied by race/ethnicity: 7.3% of white patients underwent HSCT, compared to 6.4% of Hispanic and 4.3% of Black patients (P < 0.001). Socioeconomic disparities were also observed: patients with insurance were more likely to receive HSCT (6.8%) compared to those without insurance (2.1%); HSCT rates increased with income, from 3.9% in the lowest quartile to 8.1% in the highest; and patients from areas with higher education levels had nearly double the HSCT rate (8.4%) compared to those from the lowest-education areas (4.5%) with P<0.001 for all. In patients with advanced-stage disease, the mOS was 10.5 months (95%CI 9.8-11.1). Patients who received HSCT had significantly improved survival compared to those who did not (mOS 110.9 vs. 11.1 months; P < 0.001). Among those who underwent HSCT, there was no significant difference in survival between auto (N=207) and allo (N=47) mOS 118.9 vs. 95.7 months; P = 0.128. A similar trend of improved survival with HSCT and no significant difference between autologous and allogeneic HSCT was observed across all racial/ethnic groups: in Hispanic patients mOS in HSCT (N=31) vs. no HSCT (N=456) 106.2 vs. 8.8 months; P < 0.001. comparison between auto and allo was not performed due to the low number of allogeneic transplants (N=2). In Black patients mOS inHSCT (N=47) vs. no HSCT (N=1,215) 69.7 vs. 8.8 months; P < 0.001 and mOS in auto vs. allo NR in both groups; P = 0.764. InCaucasian patients mOS in HSCT (N=419) vs. no HSCT (N=4,111) 111.8 vs. 8.8 months; P < 0.001 and mOS in Auto vs. allo 118.9 vs. 99.4 months; P = 0.263. On multivariate analysis, older age, male gender, black race, presence of B-symptoms at diagnosis, HIV positive status, higher comorbidity score and receiving allogeneic (vs. autologous) HSCT were associated with worse survival. In contrast, having medical insurance, receiving radiation therapy, chemotherapy, and undergoing HSCT (vs. no HSCT) were associated with improved survival. Conclusion HSCT was associated with significantly improved overall survival in patients with PTCL-NOS, especially in those with advanced-stage disease. This survival benefit was consistently observed across racial and ethnic groups. These findings might be related to transplant eligibility. However, allogeneic HSCT was linked to worse outcomes compared to autologous HSCT, likely due to higher transplant-related mortality or selection bias of more aggressive diseases to undergo allogeneic transplant. Even though the trend reflects a growing adoption of HSCT as part of treatment strategies in advanced-stage PTCL-NOS over time, transplant utilization varied significantly by sociodemographic factors (insurance, education and income level), highlighting potential disparities in access to this potentially life-prolonging therapy. Further prospective studies are needed to refine transplant strategies and improve patient selection.