[Interim results of a multicenter cohort study for Chinese Children Leukemia Group-acute lymphoblastic leukemia 2018...

Objective: To summarize the therapeutic effects of Chinese Children Leukemia Group-acute lymphoblastic leukemia (CCLG-ALL) 2018 regimen in children with T cell acute lymphoblastic leukemia (T-ALL) and to find out risk indicators for prognosis. Methods: This study was a prospective multicenter cohort study involving 299 newly diagnosed T-ALL children in 21 Grade A tertiary hospitals nationwide. All patients received CCLG-ALL 2018 regimen and clinical data for treatment efficacy evaluating was collected. Variables associated with event free survival (EFS) rate, overall survival (OS) rate and cumulative recurrence rate were evaluated by Lasso regression analysis (including variables selection, model construction and hazard ratio calculating). Results: A total of 299 newly diagnosed T-ALL children were included, accounting for 9.9% (299/3 026) of all ALL patients. Among these patients, there were 224 males and 75 females, and the age of onset was 7.0 (4.7, 10.6) years. All patients received CCLG-ALL 2018 regimen treatment. After 31.1 (17.3, 43.8) months follow-up, 3-year EFS, 3-year OS and cumulative recurrence rate of them were (83.2±2.7)%, (91.3±1.8)%, and (7.9±1.7)%, respectively. Minimal residual disease (MRD) greater than 10.00% on day 15 of induction therapy was a risk factor for EFS (HR=1.89, 95%CI 1.04-3.44), OS (HR=2.82, 95%CI 1.35-5.92), and cumulative recurrence rate (HR=3.05, 95%CI 1.46-6.34). Compared with the medium-risk group, the high-risk group had higher induction failure rate (5.2% (7/134) vs. 0 (0/145), P=0.016) and lower complete remission rate (88.8% (119/134) vs.97.9% (142/145),P=0.004). Most complications happened during induction therapy (95 cases), and the most common complication was serious infection (158 cases). Conclusions: CCLG-ALL 2018 regimen shows good prognosis. MRD greater than 10.00% on day 15 of induction therapy is a strong risk factor, which can indicate the prognosis in the early stage of the disease and guide the appropriate treatment.