Down syndrome, acute lymphoblastic leukemia, and t(8;14)(q11;q32)

Pediatric acute lymphoblastic leukemia with a t(8;14)(q11.2;q32): B-cell disease with a high proportion of Down syndrome: a Children's Oncology Group study

The rare translocation t(8;14)(q11.2;q32) has been described in patients with B-cell acute lymphoblastic leukemia (ALL), particularly patients with Down syndrome (DS). We describe patients with the t(8;14)(q11.2;q32) who were identified by the Children's Oncology Group (COG) ALL cytogenetics database, expanding our previous report of 10 patients with this translocation. Twenty-two such patients were treated with COG protocols. All patients had B-cell ALL, and seven (31.8%) had DS. None of the children with DS had an event; thus, these patients had a superior estimated 5-year event-free survival (EFS) compared to non-DS patients (100% vs. 50.1 ± 17.7%; P = 0.04). Only one patient (4.5%) had a concomitant Philadelphia chromosome t(9;22)(q34;q11.2). The cytogenetics data of two additional patients, who were not eligible for COG protocols, are also included in this report. In conclusion, ALL patients with the recurring translocation t(8;14)(q11.2;q32) have the B-cell phenotype and a high percentage have DS. Children with DS and the t(8;14)(q11.2;q34) have improved EFS using standard COG therapy compared to non-DS patients. We did not find an increased number of patients with a concomitant Philadelphia chromosome in this population.

Therapy-related acute lymphoblastic leukemia without 11q23 abnormality: report of six cases and a literature review

Therapy-related acute lymphoblastic leukemia (t-ALL) is a rare secondary leukemia following chemotherapy and/or radiotherapy for primary malignancies. Chromosomal 11q23 abnormality, frequently detected in therapy-related acute myeloid leukemia, is the most common cytogenetic alteration in t-ALL. However, t-ALL cases without 11q23 abnormality have been rarely described. We describe 6 adults with secondary t-ALL without 11q23 abnormalities following various treatment regimens for primary malignancies. We also reviewed 48 t-ALL cases, with complete chromosomal karyotyping, reported in the literature from 1992 to 2007. In the 48 cases, an 11q23 abnormality involving the MLL gene locus was the predominant chromosomal aberration (32 [67%]), followed by t(9;22) (6 [13%]) and a normal karyotype (4 [8%]). Compared with t-ALL cases with an 11q23 abnormality, cases without an 11q23 abnormality had a relatively longer latency period (median, 36 vs 19 months) and a different primary malignancy spectrum. No major difference was observed between groups in regard to age, sex, or receipt of a topoisomerase II inhibitor. The t(8;14)(q11.2;q32), a rare, nonrandom, balanced chromosomal translocation differing from the more common translocation involving c-MYC on chromosome 8q24, was seen in 1 adult t-ALL case, which may suggest another possible pathogenesis of this disease.

Cytogenetic features of acute lymphoblastic and myeloid leukemias in pediatric patients with Down syndrome: an iBFM-SG study

Children with Down syndrome (DS) have a markedly increased risk of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). To identify chromosomal changes cooperating with +21 that may provide information on the pathogenesis of these leukemias, we analyzed 215 DS-ALLs and 189 DS-AMLs. Unlike previous smaller series, a significant proportion of DS-ALLs had the typical B-cell precursor ALL abnormalities high hyperdiploidy (HeH; 11%) and t(12;21)(p13;q22) (10%). The HeH DS-ALLs were characterized by gains of the same chromosomes as non–DS-HeH, suggesting the same etiology/pathogenesis. In addition, specific genetic subtypes of DS-ALL were suggested by the significant overrepresentation of cases with +X, t(8;14)(q11;q32), and del(9p). Unlike DS-ALL, the common translocations associated with non–DS-AML were rare in DS-AML, which instead were characterized by the frequent presence of dup(1q), del(6q), del(7p), dup(7q), +8, +11, del(16q), and +21. This series of DS leukemias—the largest to date—reveals that DS-ALL is a heterogeneous disorder that comprises both t(12;21) and HeH as well as DS-related abnormalities. Furthermore, this analysis confirms that DS-AML is a distinct entity, originating through other genetic pathways than do non–DS-AMLs, and suggests that unbalanced changes such as dup(1q), +8, and +21 are involved in the leukemogenic process.

Acute lymphoblastic leukemia characterized by t(8;14)(q11.2;q32)

The t(8;14)(q11.2;q32) is emerging as an uncommon, though recurrent cytogenetic finding. As of yet, too few cases of acute lymphoblastic leukemia (ALL) characterized by this translocation have been studied to determine its prognostic significance with confidence. We therefore report three new patients (two male children and one adult female) and present their hematologic, immunophenotypic, and clinical data. The clinical and laboratory characteristics of 26 other patients with t(8;14)(q11.2;q32) are summarized. The total number of patients now reported in the literature is 29 with a mean age of 14 years. Early relapse, that is, relapse within 6 months, does not appear to be a common feature of this group. The gender distribution is 19 males: 9 females (gender not reported in one case). Twenty-three t(8;14) patients show a pre-B immunophenotype and 24 of 24, on whom information is available, achieved complete remission after induction chemotherapy for B-ALL. Approximately one third of patients with t(8;14) have Down syndrome, 19 of 27 have additional acquired cytogenetic abnormalities, 5 of these have the t(9;22), and 4 show duplication of the abnormal chromosome 14, which is derived from the t(8;14). Hemoglobin and platelet counts are low at presentation in 10 of 10 and 8 of 9 patients, respectively, and the average white blood count is 38.9 x 10(9)/L. Of the 7 patients for whom IgH status has been determined, all show rearrangement of the IgH locus. Two of the present three patients are included in this group; their IgH rearrangement was demonstrated by fluorescence in situ hybridization with IgH break-apart probes.

Acute lymphoblastic leukemia with an unusual t(8;14)(q11.2;q32): a Pediatric Oncology Group Study

We present the clinicopathologic findings and survival data on 10 patients with acute lymphoblastic leukemia (ALL) and a rare t(8;14)(q11.2;q32). There were five male and five female patients, nine Caucasians and one Black, aged 4-17 (median 10.9) years. Three had Down syndrome. Eight (80%) patients had a white blood cell (WBC) count <50 x 109/l at presentation. No patient had central nervous system involvement or a mediastinal mass. Two patients had concurrent splenomegaly and hepatomegaly. Adenopathy was absent in four, minimal in three, moderate in one and prominent in two patients. All eight cases where immunophenotyping was performed by flow cytometry showed a B-precursor phenotype with expression of CD10 (CALLA). Only one case exhibited t(8;14)(q11.2;q32) as the sole karyotypic abnormality. Three patients were classified as standard-risk and seven high-risk by NCI (National Cancer Institute) consensus risk group categories. All patients achieved complete remission and seven patients were in complete continuous remission (CCR) after chemotherapy designed for B-precursor ALL. Three patients relapsed after 23.5, 31.3 and 32.1 months of EFS; the first patient also had t(9;22)(q34;q11), the second had a WBC count of 126 x 109/l at presentation while the third patient had no high risk features except for age 10 years. Thus, from our data, the t(8;14)(q11.2;q32) does not appear to confer an increased risk of relapse. Further observations are needed to confirm this conclusion.