Allogeneic haematopoietic stem cell transplantation might overcome the poor prognosis of adult T-lineage acute lymphoblastic leukaemia with CDKN2 deletion

Abstract The clinical significance of cyclin-dependent kinase inhibitor 2 (CDKN2) deletion in adult T-lineage acute lymphoblastic leukemia (T-ALL) is still a matter of debate. This study aimed to investigate the prognostic value of CDKN2 deletion and impact of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in adult T-ALL. A total of 241 T-ALL patients were enrolled in this single-center retrospective study: 57 with CDKN2 deletion and 184 with CDKN2 wild-type (WT). CDKN2 deletion was associated with a higher white blood cell (WBC) count (P = 0.013), a greater proportion of high-risk disease (P = 0.004), and a complex karyotype (P = 0.004) than CDKN2 WT. The 5-year cumulative incidence of relapse (CIR) was 30.9% (95% CI 17.5-45.3) and 17.5% (95% CI 11.2-25.1) (P = 0.004), disease-free survival (DFS) was 39.7% (95% CI 25.6-53.4) and 53.8% (95% CI 45.1-61.7) (P = 0.002), and overall survival (OS) was 36.8% (95% CI 23.2-50.5) and 58.2% (95% CI 49.1-66.2) (P < 0.001) in patients with CDKN2 deletion and CDKN2 WT, respectively. In the multivariable analysis of the entire population, CDKN2 deletion was found to be an independent adverse prognostic factor for CIR (HR 2.79 (95% CI 1.3-6), P = 0.009), DFS (HR 1.76 (95% CI 1.1-2.79), P = 0.018), and OS (HR 1.91 (95% CI 1.19-3.07), P = 0.008). In the CDKN2 deletion subgroup, the 5-year CIR was 15.8% (95% CI 4.8-32.6) and 53.9% (95% CI 26.3-75.1) (P = 0.005), DFS was 51.8% (95% CI 30.9-69.1) and 21.1% (95% CI 7.2-39.8) (P < 0.001), and OS was 51.2% (95% CI 30.4-68.7) and 17.4% (95% CI 4.8-36.5) (P < 0.001) in patients with and without allo-HSCT, respectively. Conclusion: CDKN2 deletion is associated with poor prognosis in adult patients with T-ALL. Patients with T-ALL and CDKN2 deletions may benefit from allo-HSCT.