IKZF1PLUS alterations contribute to outcome disparities in Hispanic/Latino children with B-lymphoblastic leukemia

Alexandra E Kovach; Maximilian Wengyn; My H Vu; Andrew Doan; Gordana Raca; Deepa Bhojwani

doi:10.1002/pbc.30996

IKZF1^PLUS alterations contribute to outcome disparities in Hispanic/Latino children with B-lymphoblastic leukemia

Pediatr Blood Cancer. 2024 Apr 18:e30996. doi: 10.1002/pbc.30996. Online ahead of print.

Authors

Alexandra E Kovach^{1

2}, Maximilian Wengyn³, My H Vu^{2

4}, Andrew Doan^{2

5}, Gordana Raca^{2

6}, Deepa Bhojwani^{2

5}

Affiliations

¹ Hematopathology, Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, California, USA.
² Keck School of Medicine of University of Southern California, Los Angeles, California, USA.
³ Miller School of Medicine of University of Miami, Miami, Florida, USA.
⁴ Biostatistics Core, The Saban Research Institute, Children's Hospital Los Angeles, Los Angeles, California, USA.
⁵ Cancer and Blood Disease Institute, Children's Hospital Los Angeles, Los Angeles, California, USA.
⁶ Cytogenomics, Center for Personalized Medicine, Department of Pathology and Laboratory Medicine, Children's Hospital Los Angeles, Los Angeles, California, USA.

PMID: 38637852
DOI: 10.1002/pbc.30996

Abstract

Background: Compared to other ethnicities, Hispanics/Latinos (H/L) have a high incidence of acute lymphoblastic leukemia (ALL), enrichment of unfavorable ALL genetic subtypes, and worse outcomes, even after correcting for socioeconomic factors. We previously demonstrated increased incidence of the high-risk genetic drivers IKZF1 deletion and IGH::CRLF2 rearrangement in H/L compared to non-H/L children with B-ALL. Here in an expanded pediatric cohort, we sought to identify novel genetic drivers and secondary genetic alterations in B-ALL associated with H/L ethnicity.

Procedure: Comprehensive clinicopathologic data from patients with B-ALL treated from 2016 to 2020 were analyzed. Subtype was determined from karyotype, fluorescence in situ hybridization (FISH), chromosome microarray (CMA), and our next-generation sequencing (NGS) panel (OncoKids). Non-driver genetic variants were also examined. p-Values less than .05 (Fisher's exact test) were considered significant.

Results: Among patients with B-ALL at diagnosis (n = 273), H/L patients (189, 69.2%) were older (p = .018), more likely to present with CNS2 or CNS3 disease (p = .004), and NCI high-risk ALL (p = .014) compared to non-H/L patients. Higher incidence of IGH::CRLF2 rearrangement (B-ALL, BCR::ABL1-like, unfavorable; p = .016) and lower incidence of ETV6::RUNX1 rearrangement (favorable, p = .02) were also associated with H/L ethnicity. Among secondary (non-subtype-defining) genetic variants, B-ALL in H/L was associated with IKFZ1 deletion alone (p = .001) or with IGH::CRLF2 rearrangement (p = .003). The IKZF1^PLUS profile (IKZF1 deletion plus CDKN2A/2Bdel, PAX5del, or P2RY8::CRLF2 rearrangement without DUX4 rearrangement) was identified as a novel high-risk feature enriched in H/L patients (p = .001).

Conclusions: Our study shows enrichment of high-risk genetic variants in H/L B-ALL and raises consideration for novel therapeutic targets.

Keywords: B‐ALL; Hispanic; acute lymphoblastic leukemia; ethnicity; leukemia; pediatric.

Abstract

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