Introduction:
HSTCL is a rare, aggressive extranodal lymphoma which primarily affects adolescents and young adults. A substantial subset occurs in immunosuppressed patients.
Objectives:
Given the scarcity of large-scale data, we performed a pooled analysis to define clinical features, outcomes, and prognostic factors.
Methods:
We compiled a pooled database of confirmed HSTCL cases. Demographics, clinicopathologic and molecular profiles, therapies, and outcomes were analyzed. Kaplan–Meier survival estimates, Cox proportional hazards models, and log-rank tests were applied.
Results:
Among 450 patients, median age was 31 years, with male predominance (M:F ratio 3:1). Most presented with constitutional symptoms (78%), splenomegaly (100%) and bone marrow involvement (92%). Immunophenotypically, 80% were i/r 7+, 76% CD56+, and 77% TCRγδ+. Median overall survival (OS) was 11 months. TCR subtype significantly influenced prognosis (null > αβ = γδ > biclonal). Hemoglobin < 8 g/dl, constitutional symptoms, and marrow involvement predicted worse OS. Treatment conferred incremental benefit: no therapy (1 mo), splenectomy (S; 4 mo), chemotherapy (CT; 7 mo), S+CT (18 mo) and stem cell transplantation (44 vs. 30 mo for SCT+S). Splenectomy did not improve survival beyond SCT. Outcomes were similar with auto- vs. allo-SCT, though allo-SCT showed a survival plateau. Immunosuppression adversely impacted OS. There was no OS difference between immunosuppression with and without TNFα inhibitors. Complete response and first-line therapy with L-asparaginase or platinum-based regimens were associated with superior survival.
Conclusions:
This pooled study refines the epidemiology and clinicopathology of HSTCL, underscoring the prognostic significance of immunosuppression, TCR subtype, treatment strategy, and depth of response.
