Impact of primary organ site of involvement by peripheral T-cell lymphoma not otherwise specified on survival

Introduction: Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) is a rare, highly heterogeneous group of mature T-cell neoplasms that historically has been associated with poor outcomes. We sought to investigate the influence of primary disease site on PTCL-NOS outcomes using a large national cancer registry.Methods: Baseline clinical and demographic data including primary organ of involvement and Ann Arbor disease stage were extracted from the SEER database. Patients were grouped into nine organ system groups and compared to nodal disease acting as a control. Cox regression models were utilized for adjusted survival analyses.Results: A total of 3095 patients were identified in the SEER database and included in the final analysis. The median age was 61 and a majority of patients were male (60%) and identified as non-Hispanic white (68%). A plurality of patients had stage IV disease (32%). Lymph nodes and spleen were the most common primary disease sites (67%), while central nervous system was the least common (1%). Patients with early-stage PTCL-NOS of the gastrointestinal/genitourinary systems had worse overall survival [HR = 1.97 (1.50-2.59); p < 0.001] and lymphoma-specific survival [HR = 1.74 (1.26-2.40); p < 0.001] which was statistically significant even after adjusting for other variables. Early-stage PTCL-NOS of the central nervous system also had worse overall survival [HR = 1.90 (1.11-3.27); p = 0.020] and lymphoma-specific survival [HR = 2.11 (1.17-3.80); p = 0.013]. Early-stage PTCL-NOS of the skin had better overall survival [HR = 0.54 (0.42-0.68); p < 0.001] and lymphoma-specific survival [HR = 0.388 (0.28-0.53); p < 0.001] which was statistically significant even after adjustments.Conclusion: Our findings suggest an association between primary organ involved by PTCL-NOS and both overall and lymphoma-specific survival even after adjusting for common variables. These results warrant validation in future prospective studies.