Paediatric‐inspired regimen reduces central nervous system relapse in adult acute lymphoblastic leukaemia

Central nervous system (CNS) is the common site of extramedullary relapse in adult acute lymphoblastic leukaemia (ALL) and the outcome of CNS relapse patients remains poor. This study aimed to investigate whether a paediatric-inspired chemotherapy regimen can reduce CNS relapse in adult ALL compared to the adult regimen. A total of 1005 newly diagnosed adult patients with ALL were enrolled in this study, including 596 patients who received the Hyper-CVAD (cyclophosphamide, vincristine, doxorubicin[adriamycin], and dexamethason) adult regimen and 409 patients who treated with the Precision Classification-Directed Target Total Therapy-ALL-2016 (PDT-ALL-2016) paediatric-inspired chemotherapy regimen. 11.24% of patients treated with the adult regimen (67/596) experienced a CNS recurrence, whereas only 7.09% of patients (29/409) had CNS relapse under the paediatric-inspired chemotherapy regimen. The 5-year cumulative incidence of relapse in the CNS for the paediatric cohort and adult cohort was 7.09% and 11.24% respectively (p = 0.025). Even for patients in the high-risk group, the 5-year cumulative incidence of CNS relapse was significantly lower in the paediatric cohort compared with the adult cohort (6.75% vs. 13.7%, p = 0.003). The univariate analysis revealed that the paediatric-inspired regimen is a protective factor for reducing CNS relapse (OR = 0.6, p = 0.029). Collectively, our data suggest that paediatric-inspired chemotherapy may reduce the risk of CNS relapse in adult ALL compared to adult regimens.