[Clinical characteristics and prognosis of children with T-lineage acute lymphoblastic leukemia: a single-center study].

Objectives: To study the clinical characteristics and prognosis of T-lineage acute lymphoblastic leukemia (T-ALL) and related prognostic factors.

Methods: A retrospective analysis was conducted on the children with T-ALL who were treated with the Chinese Children's Cancer Group Acute Lymphoblastic Leukemia (CCCG-ALL) regimen in Guangzhou Women and Children's Medical Center between April 2015 and December 2022.

Results: A total of 80 children were included, with a median age of 7 years and 3 months and a male/female ratio of 6:1. Among these children, the children with mediastinal mass accounted for 20% (16/80), those with central nervous system leukemia accounted for 4% (3/80), and those with testicular leukemia accounted for 1% (1/69). SIL/TAL1 was the most common fusion gene (22%, 18/80), and NOTCH1 was the most common mutation gene (69%, 37/54). The median follow-up time was 52 months, with a 5-year overall survival (OS) rate of 87.3%±4.0% and a 5-year event-free survival rate of 84.0%±4.3%. The non-central nervous system-1 group had a significantly lower 5-year OS rate than the central nervous system-1 group (66.7%±16.1% vs 90.3%±3.8%; P<0.05), and the group with minimal residual disease (MRD) ≥0.01% on day 46 of induction therapy had a significantly lower 5-year OS rate than the group with MRD <0.01% (68.6%±13.5% vs 94.8%±3.0%; P<0.05).

Conclusions: Children treated with the CCCG-ALL regimen tend to have a good treatment outcome. Non-central nervous system-1 status and MRD ≥0.01% on day 46 of induction therapy are associated with the poor prognosis in these children.