Abstract

Recurrent chromosome translocations play a critical role in the pathogenesis of ALL and many translocations have important prognostic significance. The t(8;14)(q11.2;q32) is a recurrent translocation that fuses the chromosome 8 CEBPD (CCAAT enhancer binding protein delta) gene to the IgH (immunoglobulin heavy chain) gene, leading most likely to deregulated CEPD expression. We previously reported the clinical data of 10 such patients (

Leukemia
,
2000
;
14
:
238
–240
). Using the COG ALL cytogenetics database we expand the report to include 22 patients (13 females and 9 males) with the t(8;14)(q11.2;q32). All patients with available immunophenotyping data (n=20) had B-lineage ALL. The median age at diagnosis was 9.2 years (range: 1.6 months – 17.1 years). Median diagnostic white blood cell count (WBC) was 9,950 (range: 700–172,000). Of the 22 patients, 7 were NCI standard risk and 15 were high risk. The most common additional cytogenetic abnormality was trisomy 21. Of the ten cases with trisomy 21, seven were constitutional (Down Syndrome), thus confirming previous reports that a significant fraction of t(8;14) patients (7/22; 31.8%) have Down Syndrome, which is much higher than the 3% (80/2811) overall rate of children with Down Syndrome in a recent COG ALL trial (p<0.0001). In addition to the Down Syndrome cases, one case with phenotypic Turner syndrome had a mosaic constitutional r(Y)(p11q11.2); thus, eight cases (36%) had constitutional abnormalities. Secondary abnormalities included additional X (n=5); additional 5 (n=3); Philadelphia chromosome (n=1). Two cases had a second der(14)t(8;14) and two had loss of the der(8) t(8;14), consistent with the der(14)t(8;14) as the significant abnormality. Four cases (18%) had 9p deletions compared with 11% in the overall ALL population, and two cases (9%) had abnormalities of 13q compared with 2% in the overall population. Numerically, the cases were pseudodiploid (n=12) and hyperdiploid (n=10). Children with Down Syndrome had superior estimated 5-year event-free survival of 100%, compared to non-Down patients with 50.1±17.7% (p=0.04). Overall survival was also different but did not reach statistical significance: 100% vs. 60.9±17.0% (p=0.088). In summary, the rare t(8;14)(q11.2;q32) is associated with B-lineage phenotype and occurs with greatly increased frequency in children with Down Syndrome, who have an excellent outcome with standard COG therapy as compared to non-Down Syndrome patients with this translocation.

Disclosures: No relevant conflicts of interest to declare.

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