Objective:

To summarize the long-term efficacy of Beijing Children's Hospital-2009-lymphoblastic lymphoma (BCH-2009-LBL) in the treatment of T-lymphoblastic lymphoma (T-LBL) in children and adolescents and to explore the prognostic factors.

Methods:

T-LBL children admitted to Beijing Children's Hospital Affiliated to Capital Medical University from January 2009 to April 2017 were retrospectively included. According to clinical stage, prognostic genes and treatment response, the children were divided into low, intermediate and high risk groups, and stratified treatment was performed according to the BCH-2009-LBL protocol, with follow-up until December 31, 2023. The clinical characteristics and therapeutic effect of each group were compared. Survival curve was drawn by Kaplan-Meier method, and the difference in survival rate between groups was compared by log-rank test. Multivariate Cox regression model was used to analyze the prognostic factors.

Results:

A total of 146 patients were included, the age of disease onset [M(Q1, Q3)] was 8.0 (1.5, 14.0) years old. There were 107 (73.3%) males and 39 (26.7%) females. Clinical staging 1 case in stage Ⅰ and 1 case in stage Ⅱ (0.7% each), 41 cases (28.1%) cases in stage Ⅲ and 103 cases(70.5%) in stage Ⅳ. There were 1 case (0.7%), 93 cases (63.7%), and 52 cases (35.6%) in the low, intermediate, and high-risk groups, respectively. The follow-up time was 121 (80, 180) months, and the 5-year and 10-year event-free survival (EFS) rates were 76.4% and 75.0%, respectively. The 5-year EFS rates of low, intermediate and high risk groups were 100.0%, 81.3% and 67.3%, respectively. There was significant difference in remission between the middle-risk group and the high-risk group on the 8th day of hormone pretreatment and at the end of induction (both P<0.05). Recurrence/progression occurred in 29 cases (recurrence rate 19.9%), and the recurrence time was 15 (3, 74) months, in which 26 cases died and only 3 cases survived. Infection-related death occurred in 6 cases (4.1%). The failure or progression of hormone pretreatment at d8 (HR=10.089, 95%CI 1.266-80.387, P=0.029) and the failure to achieve complete remission at the end of induction (mid-term evaluation) (HR=7.638, 95%CI 2.411-24.199, P=0.001) were the risk factors for EFS rate of intermediate risk group. The above indexes had no statistical significance on EFS rate in high-risk groups (all P>0.05).

Conclusions:

BCH-2009-LBL regimen shows good efficacy in the treatment of pediatric T-LBL. The failure or progression of hormone pretreatment at d8 and the failure to achieve complete remission at the end of induction (mid-term evaluation) were the risk factors for EFS rate.