Pathologic Features of Down Syndrome Myelodysplastic Syndrome and Acute Myeloid Leukemia: A Report From the Children's Oncology Group Protocol AAML0431.

CONTEXT.­: Detailed diagnostic features of acute myeloid leukemia in Down syndrome are lacking, leading to potential misdiagnoses as standard acute myeloid leukemia occurring in patients with Down syndrome. OBJECTIVE.­: To evaluate diagnostic features of acute myeloid leukemia and myelodysplastic syndrome in patients with Down syndrome. DESIGN.­: Diagnostic bone marrow samples from 163 patients enrolled in the Children's Oncology Group study AAML0431 were evaluated by using central morphologic review and institutional immunophenotyping. Results were compared to overall survival, event-free survival, GATA1 mutation status, cytogenetics, and minimal residual disease results. RESULTS.­: Sixty myelodysplastic syndrome and 103 acute myeloid leukemia samples were reviewed. Both had distinctive features compared to those of patients without Down syndrome. They showed megakaryocytic and erythroid but little myeloid dysplasia, and marked megakaryocytic hyperplasia with unusual megakaryocyte morphology. In acute myeloid leukemia cases, megakaryoblastic differentiation of blasts was most common (54 of 103, 52%); other cases showed erythroblastic (11 of 103, 11%), mixed erythroid/megakaryoblastic (20 of 103, 19%), or no differentiation (10 of 103, 10%). Myelodysplastic syndrome and acute myeloid leukemia cases had similar event-free survival and overall survival. Leukemic subgroups showed interesting, but not statistically significant, trends for survival and minimal residual disease. Cases with institutional diagnoses of French American British M1-5 morphology showed typical features of Down syndrome disease, with survival approaching that of other cases. CONCLUSIONS.­: Myelodysplastic syndrome and acute myeloid leukemia in Down syndrome display features that allow discrimination from standard cases of disease. These distinctions are important for treatment decisions, and for understanding disease pathogenesis. We propose specific diagnostic criteria for Down syndrome-related subtypes of acute myeloid leukemia and myelodysplastic syndrome.

Genotypic and clinical heterogeneity within NCCN favorable-risk acute myeloid leukemia.

The National Comprehensive Cancer Network (NCCN) defines the following types of acute myeloid leukemia (AML) as favorable-risk: acute promyelocytic leukemia with t(15;17) (APL); AML with core-binding factor (CBF) rearrangements, including t(8;21) and inv(16) or t(16;16) without mutations in KIT (CBF-KITwt); and AML with normal cytogenetics and mutations in NPM1 (NPM1mut); or biallelic mutations in CEBPA (CEBPAmut/mut), without FLT3-ITD. Although these AMLs are categorized as favorable risk by NCCN, clinical experience suggests that there are differences in clinical outcome amongst these cytogenetically and molecularly distinct leukemias. This study compared clinical and genotypic characteristics of 60 patients with favorable-risk AML, excluding APL, and demonstrated significant differences between them. Patients with NPM1mut AML were significantly older than those in the other groups. Targeted next-generation sequencing on DNA from peripheral blood or bone marrow revealed significantly more mutations in NPM1mut AML than the other favorable-risk diseases, especially in genes related to DNA splicing and methylation. CEBPAmut/mut AMLs exhibited more mutations in transcription-related genes. Patients with NPM1mut AML and CEBPAmut/mut AML show significantly reduced overall survival in comparison with CBF-KITwt AML. These findings emphasize that favorable-risk AML patients have divergent outcomes and that differences in clinical and genotypic characteristics should be considered in their evaluation and management.

Data-Driven Iterative Refinement of Bone Marrow Testing Protocols Leads to Progressive Improvement in Cytogenetic and Molecular Test Utilization.

OBJECTIVES: To determine the effect of iterative refinement of standard ordering protocols on test utilization and results for bone marrow biopsy specimens. METHODS: Eighteen months of test utilization and result data were used to revise the protocols that determine cytogenetic and molecular test selection on bone marrow specimens and then compared with data obtained following protocol revision. RESULTS: Revision of protocols resulted in reduction in total tests and associated charges, due to a decrease in tests both concordant and discordant with the protocols. These reductions only occurred in diseases for which revisions were made and were limited to cases in which reflex testing was performed. There was an increase in the fraction of positive tests, which was also limited to reflex testing. CONCLUSIONS: Data-driven iterative revision of protocols further improves test utilization and performance, while reducing cost. Analysis of testing data can be used to continuously improve test ordering decisions.

Innovative analyses support a role for DNA damage and an aberrant cell cycle in myelodysplastic syndrome pathogenesis.

We used flow cytometry to analyze the cell cycle, DNA damage, and apoptosis in hematopoietic subsets in MDS marrow. Subsets were assigned using CD45, side scatter, CD34, and CD71. Cell cycle fractions were analyzed using DRAQ 5 (DNA content) and MPM-2 (mitoses). DNA damage was assessed using p-H2A.X, and apoptosis using Annexin V. Compared to controls, MDS patients demonstrated no increased mitoses in erythroid, myeloid, or CD34+ cells. Myeloid progenitors demonstrated increased G2 cells, which with no increased mitoses suggested delayed passage through G2. Myeloid progenitors demonstrated increased p-H2A.X, consistent with DNA damage causing this delay. Annexin V reactivity was equivalent in MDS and controls. Results for each parameter varied among hematopoietic compartments, demonstrating the need to analyze compartments separately. Our results suggest that peripheral cytopenias in MDS are due to delayed cell cycle passage of marrow progenitors and that this delayed passage and leukemic progression derive from excessive DNA damage.

Quantitative assessment of myeloid nuclear differentiation antigen distinguishes myelodysplastic syndrome from normal bone marrow.

By using flow cytometry, we analyzed myeloid nuclear differentiation antigen (MNDA) expression in myeloid precursors in bone marrow from patients with myelodysplastic syndrome (MDS) and control samples from patients undergoing orthopedic procedures. The median percentage of MNDA-dim myeloid precursors in MDS cases was 67.4% (range, 0.7%-97.5%; interquartile range, 44.9%-82.7%) of myeloid cells, with bimodal MNDA expression in most MDS samples. Control samples demonstrated a median MNDA-dim percentage in myeloid precursors of 1.2% (range, 0.2%-13.7%; interquartile range, 0.6%-2.7%), with no bimodal pattern in most samples. The area under the receiver operating characteristic curve for MNDA-dim percentage in myeloid precursors was 0.96 (P = 9 × 10(-7)). Correlation of MNDA-dim levels with World Health Organization 2008 morphologic diagnoses was not significant (P = .21), but correlation with patient International Prognostic Scoring System scores suggested a trend (P = .07). Flow cytometric assessment of MNDA in myeloid precursors in bone marrow may be useful for the diagnosis of MDS.

PCR detection of Histoplasma capsulatum var. capsulatum in whole blood of a renal transplant patient with disseminated histoplasmosis.

We report the identification of Histoplasma capsulatum var. capsulatum from whole blood in a renal transplant patient with disseminated histoplasmosis using colorimetric microtiter-plate PCR. This modality demonstrated utility in reaching a definitive diagnosis in a timely manner. Blood fungal cultures in this case remained negative, suggesting that molecular assays may facilitate the laboratory diagnosis of disseminated histoplasmosis.

Phase II evaluation of an intensified induction therapy with standard daunomycin and cytarabine followed by high dose cytarabine for adults with previously untreated acute myeloid leukemia: a Southwest Oncology Group study (SWOG-9500).

Induction therapy for acute myeloid leukemia (AML) usually consists of 7 days of cytarabine at 100-200 mg/m(2)/day and an anthracycline. Such combinations produce complete response (CR) rates of 60-80% in patients with de novo AML. On the basis of a previous report, suggesting a higher CR rate using a regimen of standard daunomycin and cytarabine followed by 3 days of high-dose cytarabine (HDAC), 101 eligible patients received this regimen in a phase II trial. Sixty patients [59%, 95% confidence interval (CI) 49-69%] achieved a CR, and 10 patients died of infection during induction. Although cytogenetic risk group affected overall survival (P = 0.0016) and relapse-free survival (P = 0.0043), it had no impact on CR rate (P = 0.63). Patients received postremission therapy with repetitive courses of alternate day high-dose cytarabine; this was associated with considerable toxicity and the majority of patients could not receive all of the scheduled postremission therapy. The estimated median survival was 23 months (95% CI 15-34 months), and the estimated probability of surviving 5 years was 34% (95% CI 24-43%). The results of this intensive induction regimen were similar to that seen in previous trials and were not as promising as reported in the previous pilot study.

Dysregulated human myeloid nuclear differentiation antigen expression in myelodysplastic syndromes: evidence for a role in apoptosis.

Reduced levels of human myeloid nuclear differentiation antigen (MNDA) gene transcripts have been detected in both familial and sporadic cases of myelodysplastic syndromes (MDS). Numerous reports implicate elevated apoptosis/programmed cell death and death ligands and their receptors in the pathogenesis of MDS. MNDA and related proteins contain the pyrin domain that functions in signaling associated with programmed cell death and inflammation. We tested the hypothesis that MNDA is involved in the regulation of programmed cell death in human myeloid hematopoietic cells. Clones of K562 cells (MNDA-null) that expressed ectopic MNDA protein were established using retroviral transduction. MNDA-expressing K562 clones were resistant to tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-induced apoptosis, but were not protected from programmed cell death induced with genotoxic agents or H(2)O(2). MNDA protein expression assessed in control and intermediate and high-grade MDS marrows showed several patterns of aberrant reduced MNDA. These variable patterns of dysregulated MNDA expression may relate to the variable pathophysiology of MDS. We propose that MNDA has a role regulating programmed cell death in myeloid progenitor cells, and that its down-regulation in MDS is related to granulocyte-macrophage progenitor cell sensitivity to TRAIL-induced programmed cell death.

Age and acute myeloid leukemia.

We conducted a retrospective analysis of 968 adults with acute myeloid leukemia (AML) on 5 recent Southwest Oncology Group trials to understand how the nature of AML changes with age. Older study patients with AML presented with poorer performance status, lower white blood cell counts, and a lower percentage of marrow blasts. Multidrug resistance was found in 33% of AMLs in patients younger than age 56 compared with 57% in patients older than 75. The percentage of patients with favorable cytogenetics dropped from 17% in those younger than age 56 to 4% in those older than 75. In contrast, the proportion of patients with unfavorable cytogenetics increased from 35% in those younger than age 56 to 51% in patients older than 75. Particularly striking were the increases in abnormalities of chromosomes 5, 7, and 17 among the elderly. The increased incidence of unfavorable cytogenetics contributed to their poorer outcome, and, within each cytogenetic risk group, treatment outcome deteriorated markedly with age. Finally, the combination of a poor performance status and advanced age identified a group of patients with a very high likelihood of dying within 30 days of initiating induction therapy. The distinct biology and clinical responses seen argue for age-specific assessments when evaluating therapies for AML.

Randomized use of cyclosporin A (CsA) to modulate P-glycoprotein in children with AML in remission: Pediatric Oncology Group Study 9421.

Relapse is a major obstacle in the cure of acute myeloid leukemia (AML). The Pediatric Oncology Group AML Study 9421 tested 2 different strategies to improve event-free survival (EFS) and overall survival (OS). Patients were randomized to receive standard-dose DAT (daunorubicin, cytarabine, and thioguanine) or high-dose DAT during induction. To interfere with P-glycoprotein (P-gp)-dependent drug efflux, the second randomization tested the benefit of cyclosporine (CsA) added to consolidation chemotherapy. Of the 282 children randomly assigned to receive standard DAT induction, 248 (87.9%) achieved remission compared to 253 (91%) of the 278 receiving high-dose DAT (P = ns). Children with HLA-identical sibling donors who achieved a complete remission received an allogeneic bone marrow transplant as consolidation. For the 83 patients receiving a matched related donor bone marrow transplantation (BMT), the 3-year disease-free survival (DFS) is 67%. Of the 418 children who achieved remission and went on to consolidation with and without CsA, the DFS was 40.6% and 33.9%, respectively (P = .24). Overexpression of P-gp was infrequent (14%) in this pediatric population. In this study, intensifying induction with high-dose DAT and the addition of CsA to consolidation chemotherapy did not prolong the durations of remission or improve overall survival for children with AML.

S100P is selectively upregulated in tumor cell lines challenged with DNA cross-linking agents.

Bifunctional alkylating agents that cross-link DNA are implicated in the pathogenesis of therapy related myelodysplastic syndromes (MDS) and MDS related acute myeloid leukemia (MDR-AML). We exposed HL60 cells to the highest level of bifunctional alkylating nitrogen mustard mechlorethamine (HN2) that was consistent with recovery following suppressed growth. Microarray analyses showed minor changes in transcripts in HN2 treated cells. A moderate up-regulation of S100P mRNA was consistently observed after 1 day of exposure to bifunctional alkylating agents and expression was not induced with monofunctional agents. Elevated S100P protein/antigen was not detected until days later in a subset of non-mitotic G2 cells. Elevated S100P protein persisted over the course of a delayed recovery phase. The results confirm recent reports indicating that S100P is a survival factor. In addition, our results indicate that S100P has a specific role in G2 cell function associated with a prolonged phase of recovery after exposure to bifunctional alkylating agents.

Overexpression of GSTA2 protects against cell cycle arrest and apoptosis induced by the DNA inter-strand crosslinking nitrogen mustard, mechlorethamine.

The effectiveness of bifunctional alkylating nitrogen mustard compounds in chemotherapy is related to their ability to form DNA inter-strand crosslinks. Patients exposed to DNA inter-strand crosslinking (ICL) agents subsequently experience an elevated incidence of myelodysplastic syndromes (MDS) and MDS related acute myeloid leukemia. Fanconi's anemia (FA) patients are deficient in the repair of crosslink DNA damage and they experience a high incidence of MDS. These observations indicate that hematopoietic cells are specific target for the transforming effects of DNA crosslinking damage. Changes in transcript levels were characterized in human hematopoietic cells occurring in response to the nitrogen mustard, mechlorethamine (HN2), but not in response to monofunctional analogs. Only modest changes in a few gene transcripts were detected in HL60 cells exposed to levels of HN2 tittered to maximal dose that caused growth suppression with minimal cell death and allowed eventual resumption of normal cell growth. Under conditions of transient growth suppression, a subset of glutathione-S-transferase (GST) isoenzyme genes was consistently upregulated three to fourfold by HN2, but not by monofunctional analogs. Subsequent efforts to confirm the changes detected by microarray analyses revealed an unexpected dependence on treatment conditions. The GST alpha class A2 subfamily member transcripts were upregulated 24 h after a 1 h exposure to HN2 that caused an extensive, but transient block in late S/G2 cell cycle phase, but were minimally altered with continuous exposure. The 1-h exposure to HN2 caused a transient late S/G2 cell cycle arrest in both the HL-60 cell line and the Colo 320HSR human colon cancer cell line. Overexpression of GSTA2 by transient transfection protected Colo 320HSR cells against both cycle arrest and apoptosis following exposure to HN2. Overexpression of GSTA2 in Colo 320HSR cells induced after exposure to HN2 did not alter cycle arrest or apoptosis. The results indicate that human GSTA2 facilitates the protection of cells from HN2 damage and not repair. Our results are consistent with the possibility that GSTA2 polymorphisms, variable isoenzyme expression, and variable induced expression may be factors in the pathogenesis of MDS.

Pulmonary hypertension complicating bone marrow transplantation for idiopathic myelofibrosis.

Idiopathic myelofibrosis is a rare hematologic disorder that is occasionally associated with pulmonary hypertension and has been cured with bone marrow transplantation (BMT). Most cases occur in older adults, but children with similar clinical and pathologic findings have been described. The authors describe a critically ill male infant with idiopathic myelofibrosis and subtle findings suggestive of pulmonary hypertension who was treated with BMT after failing to respond to chemotherapy. After BMT, the patient's clinical course improved in all respects, but he ultimately died of progressive pulmonary hypertension.

Revised recommendations of the International Working Group for Diagnosis, Standardization of Response Criteria, Treatment Outcomes, and Reporting Standards for Therapeutic Trials in Acute Myeloid Leukemia.

An International Working Group met to revise the diagnostic and response criteria for acute myelogenous leukemia originally published in 1990, as well as to provide definitions of outcomes and reporting standards to improve interpretability of data and comparisons among trials. Since the original publication, there have been major advances in our understanding of the biology and molecular genetics of acute leukemia that are clinically relevant and warrant incorporation into response definitions. Differences from the 1990 recommendations included a category of leukemia-free state, new criteria for complete remission, including cytogenetic and molecular remissions and remission duration. Storage of viable blasts for correlative studies is important for future progress in the therapy of these disorders.

Cyclosporine inhibition of P-glycoprotein in chronic myeloid leukemia blast phase.

Chronic myeloid leukemia blast phase (CML-BP) cells commonly express the multidrug transporter, P-glycoprotein (Pgp). To determine whether Pgp inhibition improves treatment outcome in CML-BP, the Southwest Oncology Group performed a randomized, controlled trial testing the benefit of the Pgp modulator, cyclosporin A (CsA). Seventy-three eligible patients were assigned to treatment with cytarabine and infusional daunorubicin with or without intravenous CsA. Treatment with CsA yielded no improvement in treatment outcome as measured by the frequency of induction resistance (68% vs 53%), rate of complete remission or restored chronic phase (CR/CP, 8% vs 30%), and survival (3 vs 5 months). Blast expression of Pgp (63%) and LRP (71%) was common, whereas only Pgp adversely impacted the rate of CR/CP (P =.025). We conclude that Pgp has prognostic relevance in CML-BP but that the modulation of Pgp function with CsA as applied in this trial is ineffective.

Retroviral mediated expression of the human myeloid nuclear antigen in a null cell line upregulates Dlk1 expression.

The human myeloid nuclear differentiation antigen (MNDA) is a hematopoietic cell specific nuclear protein. MNDA and other related gene products interact with and alter the activity of a large number of proteins involved in regulating specific gene transcription. MNDA and related genes exhibit expression characteristics, which suggest functions unique to specific lineages of cells, in addition to mediating the effects of interferons. Cells of the human K562 myeloid line do not express MNDA and are relatively immature compared to lines that express MNDA (HL-60, U937, and THP1). The hypothesis that MNDA influences the expression of specific genes was tested by creating MNDA expressing K562 cells using stable retroviral mediated gene transfer followed by evaluation of transcription profiles. Two macroarrays containing a total of 2,350 cDNAs of known genes showed a specific up-regulation of Dlk1 expression in MNDA expressing K562 cell clones. Real time quantitative RT-PCR analysis confirmed an average of over 3- and 7-fold upregulation of Dlk1 in two clones of MNDA expressing K562 cells. The effects on Dlk1 were also confirmed by Northern blotting. Dlk1 is essential for normal hematopoiesis and abnormal expression is a proposed marker of myelodysplastic syndrome. Additional screening of transcription profiles after induced erythroid and megakaryoblastic differentiation showed no additional gene transcripts altered by the presence of MNDA. These results indicate that MNDA alters expression of a gene essential for normal hematopoiesis.

11q23 balanced chromosome aberrations in treatment-related myelodysplastic syndromes and acute leukemia: report from an international workshop.

Among 511 patients with therapy-related myelodysplastic syndrome or acute leukemia (t-MDS/t-AL) and balanced chromosome aberrations, 162 (32%) had translocations involving 11q23. The recurring translocation partners were 9p22 (48%), 19p13.3 (11%), 19p13.1 (10%), 4q21 (9%), 6q27 (6%), 1p32 (2%), 16p13.1 (2%), 10p13 (1%), and 17q25 (1%); in 9%, the translocations were seen only once. The remaining 349 patients were divided into five subgroups based on the balanced aberration: 21q22, inv(16), t(15;17), Rare, and Unique aberrations. Patients in the 11q23 subgroup had a sole cytogenetic abnormality more often than those in the 21q22, inv(16), Rare, and Unique subgroups, and a complex karyotype or -5/del(5q) and/or -7/del(7q) less often than patients in the 21q22, Rare, and Unique subgroups. Clinically, 11q23 patients had acute lymphoblastic leukemia (ALL) more often as their primary disease and a shorter latency from start of treatment for the primary disease to their t-MDS/t-AL diagnosis, except when compared with the inv(16) subgroup. The 11q23 subgroup demonstrated a younger age at t-MDS/t-AL diagnosis, but this finding was not significant when patients with AL as their primary diagnosis were excluded. Survival from the time of diagnosis of t-MDS/t-AL was significantly shorter for the 11q23 subgroup compared with that of the 21q22, inv(16), and t(15;17) subgroups (median 8 vs. 14, 28, and 29 months, respectively). Inferior survival occurred even though 11q23 patients were younger and more often received blood or marrow transplantation (BMT). Even among patients receiving BMT, 11q23 patients had a shorter median survival (9 vs. 12-31 months for the other subgroups). However, among 11q23 patients, those receiving BMT survived longer, with 1- and 5-year survivals of 43% and 18% compared with 23% and 7% for patients not transplanted. With regard to prior therapy, 11q23 patients, compared with other patients, received radiotherapy less often as their sole therapy and chemotherapy more often. They had received VP16, methotrexate, 6MP/6TG, L-asparaginase, daunorubicin, cytarabine, and VM26 more often, likely attributed to the high frequency of AL as their primary disease. More patients in the 11q23 subgroup had received doxorubicin, except in comparison with the 21q22 subgroup; more vincristine, except in comparison with the Rare and Unique subgroups; and more prednisone, except in comparison with the Unique subgroup. Patients in the 11q23 subgroup more often received alkylating agents (AAs) (86% vs. 59-82% for the other subgroups), and topoisomerase II inhibitors (TIs) (84% vs. 49-75%), and they more often reported exposure to AAs plus TIs without radiotherapy (33% vs. 12-21%), except in comparison with the 21q22 subgroup (36%). We performed a multivariate analysis to determine whether the adverse survival of 11q23 patients compared to other Workshop patients was explained by factors other than the presence of the 11q23 abnormality. Covariates in the final model were the five cytogenetic subgroup indicators, where the 11q23 subgroup was the referent (P < 0.0001); age at t-MDS/t-AL (P = 0.0036); previous exposure to lomustine (P < 0.0001) and mitoxantrone (P = 0.0225); BMT for t-MDS/t-AL (P = 0.0006); and karyotype complexity (P = 0.0114). The risk of death for 11q23 patients relative to patients in the 21q22, inv(16), t(15;17), and Unique subgroups was significant, even after adjustment for other risk factors (relative risks 2.3, 3.6, 3.1, and 1.5, respectively; P < 0.0001 for the first three comparisons and P = 0.0125 for the last). When a multivariable model was constructed, excluding patients with AL or MDS as their primary diagnosis, the relative risk of death for 11q23 patients was significantly higher than that of all five other cytogenetic subgroups. We conclude that among t-MDS/t-AL patients with balanced aberrations, 11q23 translocations are an independent adverse risk factor. Although BMT is the current therapy of choice, new treatment is required.

Proposed changes in the definitions of acute myeloid leukemia and myelodysplastic syndrome: are they helpful?

For most of the 20th century, subclassification of acute myeloid leukemia (AML) was based on the resemblance of blasts to normal hematopoiesis. This approach was standardized by the French-American-British (FAB) group. Because of limited clinical relevance, clinicians resorted to other patient characteristics to determine treatment and predict outcome in AML. A different approach based on the relationship of a case to myelodysplastic syndrome (MDS) has been proposed. The new World Health Organization (WHO) subclassification of AML includes elements of this new proposal but retains as a major category the historical subclassification. The WHO group has also proposed modifications of the FAB subclassification of MDS. These MDS proposals have generated discussion of diagnostic criteria for MDS and a philosophical discussion of whether MDS should still be considered a syndrome, or rather a specific set of diseases characterized by genetic instability and poor outcome.