Lineage switch to acute myeloid leukemia during induction chemotherapy for early T-cell precursor acute lymphoblastic leukemia with the translocation t(6;11)(q27;q23)/KMT2A-AFDN: A case report

Immunophenotypic but Not Genetic Changes Reclassify the Majority of Relapsed/Refractory Pediatric Cases of Early T-Cell Precursor Acute Lymphoblastic Leukemia

Early T-cell precursor acute lymphoblastic leukemia (ETP-ALL) develops from very early cells with the potential for both T-cell and myeloid differentiation. The ambiguous nature of leukemic blasts in ETP-ALL may lead to immunophenotypic alterations at relapse. Here, we address immunophenotypic alterations and related classification issues, as well as genetic features of relapsed pediatric ETP-ALL. Between 2017 and 2022, 7518 patients were diagnosed with acute leukemia (AL). In addition to conventional immunophenotyping, karyotyping, and FISH studies, we performed next-generation sequencing of the T-cell receptor clonal repertoire and reverse transcription PCR and RNA sequencing for patients with ETP-ALL at both initial diagnosis and relapse. Among a total of 534 patients diagnosed with T-cell ALL (7.1%), 60 had ETP-ALL (11.2%). Ten patients with ETP-ALL experienced relapse or progression on therapy (16.7%), with a median time to event of 5 months (ranging from two weeks to 5 years). Most relapses were classified as AL of ambiguous lineage (n = 5) and acute myeloid leukemia (AML) (n = 4). Major genetic markers of leukemic cells remained unchanged at relapse. Of the patients with relapse, four had polyclonal leukemic populations and a relapse with AML or bilineal mixed-phenotype AL (MPAL). Three patients had clonal TRD rearrangements and relapse with AML, undifferentiated AL, or retention of the ETP-ALL phenotype. ETP-ALL relapse requires careful clinical and laboratory diagnosis. Treatment decisions should rely mainly on initial examination data, taking into account both immunophenotypic and molecular/genetic characteristics.

A Multicenter Cohort Study on Children Suffering from Acute Lymphoblastic Leukemia: Effects of Obesity on Mortality

Background

Overweight and obesity have been reported in specific patients and disease survivors compared to other types of childhood cancer. This study is aimed at determining the effect of children's obesity on the mortality of acute lymphoblastic leukemia.

Method

Children admitted to Inner Mongolia International Mongolian Hospital from 1 January 2017 to 31 December 2020 participated in this study. 1070 children were analyzed. A multi-middle-class poll was conducted. All children under the age of 15 were followed up within 24 months of diagnosis. Overweight and obesity are identified according to the World Health Organization and the Centers for Disease Control and Prevention. Premature death and reoccurrence of emergencies are the main consequences.

Results

The initial ethical rate for the first 24 months of testing was 19.9% (NS 213). The lowest cancer survival rate (DFS) was childhood obesity (73%) (24 months), compared with average weight (81%). Diagnosis of overweight/obesity is a predictor of early death (WHO: HR = 1.4, 95% CI: 1.0-2.0; CDC: HR = 1.6, 95% CI: 1.1-2.3). However, there was no association between overweight and obesity (WHO: HR = 1.5, 95% effective interval: 0.9-2.5; CDC: human resources = 1.0, 95% effective interval: 0.6-1.6) and obesity (WHO: HR = 1.5, 95% effective interval: 0.7-3.2; CDC: HR = 1.4, 95% effective interval: 0.9-2.3). Early recurrence was observed.

Conclusion

Overweight and obese people belong to the subclass with a high risk of death in the treatment of leukemia.

To B- or not to B-: A review of lineage switched acute leukemia

Acute leukemia is a heterogeneous disorder of hematologic malignancies composed primarily of hematopoietic precursors that have acquired unregulated self-renewal and proliferation. Hematology classification systems typically divide these neoplasms into lymphoid (B- or T-) and myeloid-lineage subtypes, with therapy dependent upon this distinction. Infrequently, certain acute leukemias may undergo a complete lineage switch at relapse, subsequently complicating the diagnosis and treatment of these recurrent diseases. Transformation from B-lineage to myeloid lineage is the most common switch observed, and is frequently associated with a balanced 11q23 translocation, involving KMT2A. The mechanisms involved in the lineage-switch are unclear, but modern therapies targeting the B-cell-specific marker, CD19, have proven to promote this conversion as one means of treatment escape. Broadly speaking, therapy-mediated selection of alternate lineage-committed subclones derived from the same initial pluripotent progenitors, clonal evolution and reprogramming of lineage-committed blasts, and de novo clonally unrelated leukemias may account for the clinical impression of lineage switched acute leukemia during treatment. This review will explore the phenomenon and potential mechanisms of lineage transformation during the treatment of acute leukemia.