Duplication 1q is highly correlated with poor prognosis in high hyperdiploid pediatric B-acute lymphoblastic leukemia.

BACKGROUND

The role of structural abnormalities in high hyperdiploidy (HeH) has been debatable, with few studies that addressed recurrent translocations with concurrent HeH (t-HeH). We aimed at the characterization of HeH cases in pediatric B-acute lymphoblastic leukemia (B-ALL) patients with special emphasis on the structural abnormalities including t-HeH.

PATIENTS AND

METHODS

Our study included all patients diagnosed with HeH over the period from January 2016 to April 2019 presenting to the Pediatric Oncology Department, National Cancer Institute, Cairo University.

RESULTS

Among 480 de novo B-ALL pediatric patients, HeH was detected in eighty (16.7%) cases with a median age of 5 years. t-HeH was identified in 17/480 (3.5%) cases: 9(1.9%) with t(12;21), 7(1.5%) with t(9;22), and 1(0.2%) with t(4;11). Duplication (1q) was the most prevalent structural abnormality in c-HeH (hyperdiploidy without recurrent translocations) (n = 12,15%). Children ≥10 years or presenting with white blood cells (WBC) ≥50 × 109 /L) had an inferior 3 year-overall survival as compared to younger children (P = .003), and to lower WBC (P = .02). Duplication (1q) was an independent adverse parameter on the disease-free survival (DFS) of c-HeH patients (P = .004).

CONCLUSIONS

Older age and WBC ≥ 50 × 109 /L were adverse prognostic factors. Duplication (1q) is correlated with lower DFS in c-HeH patients. t-HeH has distinct patterns of chromosomal gain.