Association of CD34 Expression with Future Relapse in Pediatric T-cell Acute Lymphoblastic Leukemia

Background: Developing novel prognostic markers is crucial for childhood T-cell acute lymphoblastic leukemia (T-ALL). Objectives: This study aimed to investigate whether the prognostic impact of CD34, a progenitor marker, is associated with outcomes.Methods: This retrospective cohort study included 82 risk-adapted pediatric patients with T-ALL who were treated under the National Protocol of Childhood ALL in China (NPCLC)-ALL2008 from March 2008 to December 2016. Results: CD34 expression was observed in 37.8% of all T-ALL patients, with a median expression level of 62.7%. Patients with CD34 expression had a favorable event-free survival (EFS, 74.2% [66.3% - 82.1%]) with a hazard ratio of 0.69 (P = 0.33) and a reduced cumulative incidence of relapse (CIR, 22.6% [15.0% - 30.2%]; P = 0.86) at five years. Even after adjusting for potential factors and competing events in multivariable regression models, there was no connection between the CD34 immunophenotype and the risk of recurrence. Conclusions: CD34 expression did not serve as a predictive factor for relapse in this limited series. Larger multicenter studies are recommended to determine whether this biomarker at initial diagnosis can predict outcomes.