Among pediatric patients with newly diagnosed T-cell acute lymphoblastic leukemia (T-ALL), central nervous system status (CNS-S) appears to predict for both event-free survival and overall survival (EFS and OS, respectively), according to research published in Blood.
In recent years, treatment strategies for T-ALL and B-cell ALL have diverged. There remain groups that advocate for use of prophylactic cranial radiation therapy (CRT) among pediatric patients and young adults with T-ALL, although this strategy carries significant risks, including neurocognitive problems, endocrinopathies, and the potential for secondary malignancies.
For this analysis of Children’s Oncology Group trials AALL0434 (ClinicalTrials.gov Identifier: NCT00408005) and AALL1231 (ClinicalTrials.gov Identifier: NCT02112916), which, respectively, evaluated the safety and efficacy of nelarabine and bortezomib, researchers evaluated the prognostic impact of CNS-S among patients with newly diagnosed T-ALL, of whom a proportion received CRT.
Overall, data from 2164 patients were included, of whom 1550 were enrolled to AALL0434 while 614 were enrolled to AALL1231; 90.8% of patients in the former received CRT, while 88.2% of patients in the latter study underwent intensified chemotherapy to eliminate a need for CRT. Furthermore, in the overall cohort, 1564 (72.3%) patients had CNS-1, 441 (20.4%) had CNS-2 (20.4%), and 159 (7.3%) had CNS-3.
Analysis showed that 4-year EFS was similar in the CNS-1 and CNS-2 groups (85.1% and 83.2%, respectively), though was worse among those with CNS-3 (71.8%; P = .0004). Furthermore, 4-year OS was worse in the CNS-3 group (82.7%) compared with the CNS-1 and -2 groups (90.1% and 90.5%, respectively; P = .005).
No EFS or OS differences were noted between CNS-1 and -2, regardless of whether CRT or novel agents were used. Patients with CNS-3 did, however, benefit from nelarabine, with a 4-year disease-free survival rate of 93.1%. Notably, all patients with CNS-3 received CRT.
“In our experience, effective therapies will likely be most useful when incorporated early in the treatment course, whereas, it is still possible to consolidate the CNS compartment for patients who are at the highest risk for relapse or disease progression,” the authors wrote in their report.
Disclosures: Some study authors declared affiliations with biotech, pharmaceutical, or device companies. Please see the original reference for a full list of disclosures.
Gossai NP, Devidas M, Chen Z, et al. Central nervous system status is prognostic in T-cell acute lymphoblastic leukemia: a Children’s Oncology Group report. Blood. 2023;141(15):1802-1811. doi:10.1182/blood.2022018653