Proposals for standardized protocols for cytogenetic analyses of acute leukemias, chronic lymphocytic leukemia, chronic myeloid leukemia, chronic myeloproliferative disorders, and myelodysplastic syndromes

Prognostic Factors of Pediatric Acute Myeloid Leukemia Patients with t(8;21) (q22;q22): A Single-Center Retrospective Study

This retrospective study aimed to analyze the treatment effect and prognostic factors of pediatric acute myeloid leukemia (AML) patients with t(8;21). A total of 268 newly diagnosed pediatric AML (pAML) enrolled from 1 January 2005 to 31 December 2022 were retrospectively reviewed, and 50 (18.7%) patients harbored t(8;21) translocation. CR rate, OS, EFS, and RFS were assessed by multivariate Logistic and Cox regression models in these patients. Of the 50 patients, 2 patients abandoned treatment during the first induction course. Of the remaining 48 patients who received double-induction therapy and were included in the final analyses, CR1 and CR2 were 75.0% (36/48) and 95.8% (46/48), respectively. The overall three-year OS, EFS, and RFS were 68.4% (95% CI, 55.0-85.1), 64.2% (95% CI, 50.7-81.4), and 65.5% (95% CI, 51.9-82.8), respectively. The presence of loss of sex chromosome (LOS) at diagnosis (n = 21) was associated with a better 3-year OS [87.5% (95% CI, 72.7-100) vs. 52.7% (95% CI, 35.1-79.3), p = 0.0089], 3-year EFS [81.6% (95% CI, 64.7-100) vs. 49.7% (95% CI, 32.4-76.4), p = 0.023], and 3-year RFS [81.6% (95% CI, 64.7-100) vs. 51.7% (95% CI, 33.9-78.9), p = 0.036] than those without LOS (n = 27), and it was also an independent good prognostic factor of OS (HR, 0.08 [95% CI, 0.01-0.48], p = 0.005), EFS (HR, 0.22 [95% CI, 0.05-0.85], p = 0.029), and RFS (HR, 0.21 [95% CI, 0.05-0.90], p = 0.035). However, extramedullary leukemia (EML) featured the independent risk factors of inferior OS (HR, 10.99 [95% CI, 2.08-58.12], p = 0.005), EFS (HR, 4.75 [95% CI, 1.10-20.61], p = 0.037), and RFS (HR, 6.55 [95% CI, 1.40-30.63], p = 0.017) in pediatric individuals with t(8;21) AML. Further analysis of combining LOS with EML indicated that the EML+LOS- subgroup had significantly inferior OS (92.9%, [95% CI, 80.3-100]), EFS (86.2%, [95% CI, 70.0-100]), and RFS (86.2%, [95% CI, 80.3-100]) compared to the other three subgroups (all p < 0.001). LOS and EML are independent prognostic factors of OS, EFS, and RFS with t(8;21) pAML patients. LOS combined with EML may help improve risk stratification.

Added value of molecular karyotype in childhood acute lymphoblastic leukemia

Background

Thanks to an improved therapeutic regimen in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL), 5 year-overall survival now exceeds 90%. Unfortunately, the 25% of children who relapse have an initial poor prognosis, potentially driven by pre-existing or emerging molecular anomalies. The latter are initially and essentially identified by cytogenetics. However, some subtle alterations are not visible through karyotyping.

Methods

Single nucleotide polymorphisms (SNP) array is an alternative way of chromosomal analysis allowing for a more in-depth evaluation of chromosomal modifications such as the assessment of copy number alterations (CNA) and loss of heterozygosity (LOH). This method was applied here in retrospective diagnosis/relapse paired samples from seven children with BCP-ALL and in a prospective cohort of 38 newly diagnosed childhood cases.

Results

In the matched study, compared to the initial karyotype, SNP array analysis reclassified two patients as poor prognosis cases. Modulation during relapse was seen for 4 CNA and 0.9 LOH. In the prospective study, SNP reclassified the 10 patients with intermediate karyotype as 7 good prognosis and 3 poor prognosis. Ultimately, in all the children tested, SNP array allowed to identify additional anomalies compared to conventional karyotype, refine its prognostic value and identify some druggable anomalies that could be used for precision medicine. Overall, the anomalies detected could be segregated in four groups respectively involved in B-cell development, cell proliferation, transcription and molecular pathways.

Conclusion

SNP therefore appears to be a method of choice in the integrated diagnosis of BCP ALL, especially for patients initially classified as intermediate prognosis. This complementary method of both cytogenetics and high throughput sequencing allows to obtain further classified information and can be useful in case of failure of these techniques.

Cytogenetics of Pediatric Acute Myeloid Leukemia: A Review of the Current Knowledge

Pediatric acute myeloid leukemia is a rare and heterogeneous disease in relation to morphology, immunophenotyping, germline and somatic cytogenetic and genetic abnormalities. Over recent decades, outcomes have greatly improved, although survival rates remain around 70% and the relapse rate is high, at around 30%. Cytogenetics is an important factor for diagnosis and indication of prognosis. The main cytogenetic abnormalities are referenced in the current WHO classification of acute myeloid leukemia, where there is an indication for risk-adapted therapy. The aim of this article is to provide an updated review of cytogenetics in pediatric AML, describing well-known WHO entities, as well as new subgroups and germline mutations with therapeutic implications. We describe the main chromosomal abnormalities, their frequency according to age and AML subtypes, and their prognostic relevance within current therapeutic protocols. We focus on de novo AML and on cytogenetic diagnosis, including the practical difficulties encountered, based on the most recent hematological and cytogenetic recommendations.

Insights into Potent Therapeutical Antileukemic Agent L-glutaminase Enzyme Under Solid-state Fermentation: A Review

AIM AND OBJECTIVE

To review the applications and production studies of reported antileukemic drug L-glutaminase under Solid-state Fermentation (SSF).

OVERVIEW

An amidohydrolase that gained economic importance because of its wide range of applications in the pharmaceutical industry, as well as the food industry, is L-glutaminase. The medical applications utilized it as an anti-tumor agent as well as an antiretroviral agent. L-glutaminase is employed in the food industry as an acrylamide degradation agent, as a flavor enhancer and for the synthesis of theanine. Another application includes its use in hybridoma technology as a biosensing agent. Because of its diverse applications, scientists are now focusing on enhancing the production and optimization of L-glutaminase from various sources by both Solid-state Fermentation (SSF) and submerged fermentation studies. Of both types of fermentation processes, SSF has gained importance because of its minimal cost and energy requirement. L-glutaminase can be produced by SSF from both bacteria and fungi. Single-factor studies, as well as multi-level optimization studies, were employed to enhance L-glutaminase production. It was concluded that L-glutaminase activity achieved by SSF was 1690 U/g using wheat bran and Bengal gram husk by applying feed-forward artificial neural network and genetic algorithm. The highest L-glutaminase activity achieved under SSF was 3300 U/gds from Bacillus sp., by mixture design. Purification and kinetics studies were also reported to find the molecular weight as well as the stability of L-glutaminase.

CONCLUSION

The current review is focused on the production of L-glutaminase by SSF from both bacteria and fungi. It was concluded from reported literature that optimization studies enhanced L-glutaminase production. Researchers have also confirmed antileukemic and anti-tumor properties of the purified L-glutaminase on various cell lines.

Practical Application of Fluorescent In Situ Hybridization Techniques in Clinical Diagnostic Laboratories

Fluorescent in situ hybridization (FISH) techniques can be used to identify a range of chromosome abnormalities that are clinically significant in many cancers. Multicolor FISH can be used to identify multiple targets, which can be simultaneously detected in individual cells using digital imaging microscopy. In an era of precision medicine there is a requirement to make a precise diagnosis and to have a molecular classification of the tumor that can guide therapy. Cancer genomics is now regarded as a sub-specialism in pathology and genomic testing needs to be robustly integrated into the routine diagnostic practice.The FISH techniques described in this chapter have been developed over many years in a busy hematopathology diagnostic laboratory. We describe robust in-house methods for both liquid samples (blood and bone marrow mainly) and formalin-fixed paraffin-embedded (FFPE) tissue biopsies that allow for large numbers of slides to be set up in batches. The techniques described are for interphase cells in tissues where metaphase chromosome techniques are generally not applicable. Some of the FISH tests need to be carried out as an "out-of-hours" emergency test to make a critical diagnosis while others provide prognostic information and are used to guide downstream patient management.

Cytogenetic and molecular genetic characterization of KMT2A-PTD positive acute myeloid leukemia in comparison to KMT2A-Rearranged acute myeloid leukemia

To define the biological differences in acute myeloid leukaemia (AML) with KMT2A gene involvements and their prognostic impact, we compared 190 de novo AML patients at diagnosis, 95 harbouring KMT2A-rearrangement (KMT2Ar) and 95 KMT2A-PTD by performing cytogenetic and molecular genetic analyses. Both AML subtypes had an unfavourable outcome, particularly in patients > 60 years. Patients with KMT2Ar were younger compared to patients with KMT2A-PTD (mean 52 vs 65 years, p < 0.001) and had a higher rate of additional cytogenetic abnormalities (ACA) (46% vs 25% of cases). In both groups, occurrence of ACA did not influence the overall survival (OS). Regarding molecular genetics, 66% of patients with KMT2Ar and 99% of patients with KMT2A-PTD had additional gene mutations. In multivariate analysis, KRAS mutations and 10p12 rearrangement resulted as adverse prognostic factors in KMT2Ar subgroup. In the KMT2A-PTD group, apart from age, only the occurrence of DNMT3A non-R882 mutations correlated with shorter OS.

Pre-analytical parameters associated with unsuccessful karyotyping in myeloid neoplasm: a study of 421 samples

Cytogenetics is essential in myeloid neoplasms (MN) and pre-analytical variables are important for karyotyping. We assessed the relationship between pre-analytical variables (time from collection to sample processing, material type, sample cellularity, and diagnosis) and failures of karyotyping. Bone marrow (BM, n=352) and peripheral blood (PB, n=69) samples were analyzed from acute myeloid leukemia (n=113), myelodysplastic syndromes (n=73), myelodysplastic syndromes/myeloproliferative neoplasms (n=17), myeloproliferative neoplasms (n=137), and other with conclusive diagnosis (n=6), and reactive disorders/no conclusive diagnosis (n=75). The rate of unsuccessful karyotyping was 18.5% and was associated with the use of PB and a low number of nucleated cells (≤7×10³/µL) in the sample. High and low cellularity in BM and high and low cellularity in PB samples showed no metaphases in 3.9, 39.7, 41.9, and 84.6% of cases, respectively. Collecting a good BM sample is the key for the success of karyotyping in MN and avoids the use of expensive molecular techniques.

European recommendations and quality assurance for cytogenomic analysis of haematological neoplasms

Cytogenomic investigations of haematological neoplasms, including chromosome banding analysis, fluorescence in situ hybridisation (FISH) and microarray analyses have become increasingly important in the clinical management of patients with haematological neoplasms. The widespread implementation of these techniques in genetic diagnostics has highlighted the need for guidance on the essential criteria to follow when providing cytogenomic testing, regardless of choice of methodology. These recommendations provide an updated, practical and easily available document that will assist laboratories in the choice of testing and methodology enabling them to operate within acceptable standards and maintain a quality service.

Overall survival of Brazilian acute myeloid leukemia patients according to the European LeukemiaNet prognostic scoring system: a cross-sectional study

Prognostic stratification in acute myeloid leukemia (AML) relies, mostly, on cytogenetics and molecular features of leukemic blasts. The LeukemiaNet prognostic scoring system has been proposed as a standardized way of evaluating prognosis in AML. We have analysed outcomes in 65 AML cases (median age of 54 years, range 18-82) treated at five hematology centers in Brazil stritified according to the European Leukemia Net (ELN) recommendations for cytogenetic and molecular analysis. We classified patients as favorable (N = 13), intermediate-1 (N = 25), intermediate-2 (N = 15), or adverse risk (N = 9). Bone marrow transplantation (BMT) was performed in 13 patients (21%). Median follow-up was 12 months. The median overall survival (OS) for all patients was 12.4 months. Median OS was 19.8, 12.4, 10.1, and 10.4 months (p = 0.24) for patients in the favorable, intermediate-1, intermediate-2, and adverse groups, respectively. Among patients receiving BMT, median OS was 26.8 months. The ELN is a valuable tool for prognostic stratification of AML patients treated in Brazil. Nevertheless, its usefulness is limited when compared to data from developed countries.

Amyloid precursor protein has clinical and prognostic significance in AML1-ETO-positive acute myeloid leukemia

Amyloid precursor protein (APP) has been reported to be highly expressed in acute myeloid leukemia (AML)1-eight-twenty one (ETO)-positive AML. In the present study, the clinical and prognostic significance of APP expression was assessed in 65 patients with AML1-ETO-positive AML using reverse transcription-quantitative polymerase chain reaction. The patients were divided into an APP-high expression (APP-H) group (n=32) and an APP-low expression (APP-L) group (n=33) according to the cut-off value of APP relative expression, which was calculated by receiver operating characteristic curve analysis. It was observed that C-KIT mutations (14/32 vs. 3/33, P=0.009), white blood cell count (median, 23.2×10⁹ vs. 12.4×10⁹ cells/l; P=0.011) and bone marrow cellularity (median, 91.0 vs. 84.0%; P=0.039) and incidence of extramedullary leukemia (11/32 vs. 3/33, P=0.013) were all significantly increased in the APP-H group compared with the APP-L group. Furthermore, significantly lower rate of cumulative two-cycle complete remission (83.9 vs. 100%, P=0.016), major molecular remission following two courses of consolidation (34.5 vs. 71.4%, P=0.005), and poorer relapse-free survival (RFS) (33.5±5.2% vs. 76.3±6.9%, P<0.001) and overall survival (OS) (44.5±7.0% vs. 81.9±5.8%, P=0.002) were associated with APP overexpression. Multivariate analysis revealed that APP overexpression was a significant adverse factor affecting both RFS and OS. Taken together, these data suggest that APP may be correlated with C-KIT mutations and involved in leukemia cell proliferation, and its overexpression has an adverse effect on the prognosis in AML1-ETO-positive AML.

Initial Diagnostic Workup of Acute Leukemia: Guideline From the College of American Pathologists and the American Society of Hematology

CONTEXT

- A complete diagnosis of acute leukemia requires knowledge of clinical information combined with morphologic evaluation, immunophenotyping and karyotype analysis, and often, molecular genetic testing. Although many aspects of the workup for acute leukemia are well accepted, few guidelines have addressed the different aspects of the diagnostic evaluation of samples from patients suspected to have acute leukemia.

OBJECTIVE

- To develop a guideline for treating physicians and pathologists involved in the diagnostic and prognostic evaluation of new acute leukemia samples, including acute lymphoblastic leukemia, acute myeloid leukemia, and acute leukemias of ambiguous lineage.

DESIGN

- The College of American Pathologists and the American Society of Hematology convened a panel of experts in hematology and hematopathology to develop recommendations. A systematic evidence review was conducted to address 6 key questions. Recommendations were derived from strength of evidence, feedback received during the public comment period, and expert panel consensus.

RESULTS

- Twenty-seven guideline statements were established, which ranged from recommendations on what clinical and laboratory information should be available as part of the diagnostic and prognostic evaluation of acute leukemia samples to what types of testing should be performed routinely, with recommendations on where such testing should be performed and how the results should be reported.

CONCLUSIONS

- The guideline provides a framework for the multiple steps, including laboratory testing, in the evaluation of acute leukemia samples. Some aspects of the guideline, especially molecular genetic testing in acute leukemia, are rapidly changing with new supportive literature, which will require on-going updates for the guideline to remain relevant.

Accurate quantification of chromosomal lesions via short tandem repeat analysis using minimal amounts of DNA

Background

Cytogenetic aberrations such as deletion of chromosome 5q (del(5q)) represent key elements in routine clinical diagnostics of haematological malignancies. Currently established methods such as metaphase cytogenetics, FISH or array-based approaches have limitations due to their dependency on viable cells, high costs or semi-quantitative nature. Importantly, they cannot be used on low abundance DNA. We therefore aimed to establish a robust and quantitative technique that overcomes these shortcomings.

Methods

For precise determination of del(5q) cell fractions, we developed an inexpensive multiplex-PCR assay requiring only nanograms of DNA that simultaneously measures allelic imbalances of 12 independent short tandem repeat markers.

Results

Application of this method to n=1142 samples from n=260 individuals revealed strong intermarker concordance (R²=0.77–0.97) and reproducibility (mean SD: 1.7%). Notably, the assay showed accurate quantification via standard curve assessment (R²>0.99) and high concordance with paired FISH measurements (R²=0.92) even with subnanogram amounts of DNA. Moreover, cytogenetic response was reliably confirmed in del(5q) patients with myelodysplastic syndromes treated with lenalidomide. While the assay demonstrated good diagnostic accuracy in receiver operating characteristic analysis (area under the curve: 0.97), we further observed robust correlation between bone marrow and peripheral blood samples (R²=0.79), suggesting its potential suitability for less-invasive clonal monitoring.

Conclusions

In conclusion, we present an adaptable tool for quantification of chromosomal aberrations, particularly in problematic samples, which should be easily applicable to further tumour entities.

Chromothripsis Is a Recurrent Genomic Abnormality in High-Risk Myelodysplastic Syndromes

To explore novel genetic abnormalities occurring in myelodysplastic syndromes (MDS) through an integrative study combining array-based comparative genomic hybridization (aCGH) and next-generation sequencing (NGS) in a series of MDS and MDS/myeloproliferative neoplasms (MPN) patients. 301 patients diagnosed with MDS (n = 240) or MDS/MPN (n = 61) were studied at the time of diagnosis. A genome-wide analysis of DNA copy number abnormalities was performed. In addition, a mutational analysis of DNMT3A, TET2, RUNX1, TP53 and BCOR genes was performed by NGS in selected cases. 285 abnormalities were identified in 71 patients (23.6%). Three high-risk MDS cases (1.2%) displayed chromothripsis involving exclusively chromosome 13 and affecting some cancer genes: FLT3, BRCA2 and RB1. All three cases carried TP53 mutations as revealed by NGS. Moreover, in the whole series, the integrative analysis of aCGH and NGS enabled the identification of cryptic recurrent deletions in 2p23.3 (DNMT3A; n = 2.8%), 4q24 (TET2; n = 10%) 17p13 (TP53; n = 8.5%), 21q22 (RUNX1; n = 7%), and Xp11.4 (BCOR; n = 2.8%), while mutations in the non-deleted allele where found only in DNMT3A (n = 1), TET2 (n = 3), and TP53 (n = 4). These cryptic abnormalities were detected mainly in patients with normal (45%) or non-informative (15%) karyotype by conventional cytogenetics, except for those with TP53 deletion and mutation (15%), which had a complex karyotype. In addition to well-known copy number defects, the presence of chromothripsis involving chromosome 13 was a novel recurrent change in high-risk MDS patients. Array CGH analysis revealed the presence of cryptic abnormalities in genomic regions where MDS-related genes, such as TET2, DNMT3A, RUNX1 and BCOR, are located.

Subtype-specific patterns of molecular mutations in acute myeloid leukemia

Acute myeloid leukemia (AML) can be grouped into morphologically or genetically defined subtypes. Today, the AML phenotype-genotype associations, that is, FAB/WHO (French-American-British/World Health Organization) definitions and recurrent molecular mutations, are not fully understood. Therefore, we evaluated the impact of molecular mutations on the AML differentiation stage by molecular profiling of 4373 adult de novo AML patients in 7 cytomorphological subtypes. We investigated mutations in 20 genes, including myeloid transcription factors (CEBPA, RUNX1), tumor suppressors (TP53, WT1), DNA modifiers (DNMT3A, IDH1/2, TET2), chromatin modifiers (ASXL1, MLL), signal transduction genes (FLT3, KRAS, NRAS) and NPM1. The most frequently mutated genes per cytomorphological subtype were RUNX1 in M0 (43%), NPM1 in M1 (42%), DNMT3A in M2 (26%), NPM1 in M4 (57%), M5a (49%) and M5b (70%) and TP53 in M6 (36%). Although some gene mutations were frequent in several cytomorphological subtypes, a series of associations of co-occurring mutations with distinct phenotypes were identified for molecularly defined subcohorts. FLT3, NPM1 and WT1 mutations were associated with an immature phenotype in myeloblastic AML, whereas other combinations involving ASXL1, RUNX1, MLL-PTD, CEBPA or KRAS were more frequent in myeloblastic AML with maturation. Within the NPM1 mutated subcohort, ASXL1 mutations were significantly associated with a monoblastic differentiation and DNMT3A mutations with a monocytic phenotype.

Close correlation of copy number aberrations detected by next-generation sequencing with results from routine cytogenetics in acute myeloid leukemia

High throughput sequencing approaches, including the analysis of exomes or gene panels, are widely used and established to detect tumor-specific sequence variants such as point mutations or small insertions/deletions. Beyond single nucleotide resolution, sequencing data also contain information on changes in sequence coverage between samples and thus allow the detection of somatic copy number alterations (CNAs) representing gain or loss of genomic material in tumor cells arising from aneuploidy, amplifications, or deletions. To test the feasibility of CNA detection in sequencing data we analyzed the exomes of 25 paired leukemia/remission samples from acute myeloid leukemia (AML) patients with well-defined chromosomal aberrations, detected by conventional chromosomal analysis and/or molecular cytogenetics assays. Thereby, we were able to confirm chromosomal aberrations including trisomies, monosomies, and partial chromosomal deletions in 20 out of 25 samples. Comparison of CNA detection using exome, custom gene panel, and SNP array analysis showed equivalent results in five patients with variable clone size. Gene panel analysis of AML samples without matched germline control samples resulted in confirmation of cytogenetic findings in 18 out of 22 cases. In all cases with discordant findings, small clone size (<33%) was limiting for CNA detection. We detected CNAs consistent with cytogenetics in 83% of AML samples including highly correlated clone size estimation (R = 0.85), while six out of 65 cytogenetically normal AML samples exhibited CNAs apparently missed by routine cytogenetics. Overall, our results show that high throughput targeted sequencing data can be reliably used to detect copy number changes in the dominant AML clone. © 2016 Wiley Periodicals, Inc.

[Leukemia research in Germany: the Competence Network Acute and Chronic Leukemias]

The Competence Network "Acute and Chronic Leukemias" was founded in 1997 by the consolidation of the leading leukemia study groups in Germany. Key results are the development of new trials and cooperative studies, the setup of patient registries and biobanking facilities, as well as the improvement of study infrastructure. In 2003, the concept of the competence network contributed to the foundation of the European LeukemiaNet (ELN). Synergy with the ELN resulted in cooperation on a European and international level, standardization of diagnostics and treatment, and recommendations for each leukemia and interdisciplinary specialty. The ultimate goal of the network is the cure of leukemia through cooperative research.

Array-based comparative genomic hybridization detects copy number variations with prognostic relevance in 80% of ALL with normal karyotype or failed chromosome analysis

Pretreatment cytogenetics is an important parameter for risk stratification and therapy approach in acute lymphoblastic leukemia (ALL). However, in up to 30% of cases, chromosome banding analysis (CBA) fails or reveals a normal karyotype. To characterize the subset of ALL with normal karyotype or failed CBA, we performed fluorescence in situ hybridization (FISH) or PCR for BCR-ABL1 and MLL rearrangements as well as array comparative genomic hybridization (aCGH) in 186 adult patients. We further carried out FISH for MYC in cases with Burkitt leukemia phenotype. FISH or PCR revealed one of the respective rearrangements in 22% of patients. In 80% of cases, copy number variations (CNV) were identified by aCGH. In 22% of cases, all CNV were below the resolution of CBA. On the basis of results of FISH, RT-PCR and aCGH, patients were categorized into three groups. The novel subset of patients with submicroscopic CNV only showed an overall survival at 3 years of 84% compared with 64% for patients classified as adverse abnormalities and 77% for cases with other aberrations (P=0.046). Thus, ALL with non-informative CBA can be further classified by FISH and aCGH providing prognostic information, which may be useful for a more individualized therapy.

Circulating plasma cells in newly diagnosed symptomatic multiple myeloma as a possible prognostic marker for patients with standard-risk cytogenetics

Detection of circulating plasma cells (PCs) in multiple myeloma (MM) patients is a well-known prognostic factor. We evaluated circulating PCs by flow cytometry (FC) in 104 patients with active MM at diagnosis by gating on CD38(+)  CD45(-) cells and examined their relationship with cytogenetic risk. Patients had an average follow-up of 36 months. By using a receiver operating characteristics analysis, we estimated the optimal cut-off of circulating PCs for defining poor prognosis to be 41. Patients with high-risk cytogenetics (n = 24) had poor prognosis, independently of circulating PC levels [PC < 41 vs. PC ≥ 41: overall survival (OS) = 0% vs. OS = 17%, P = not significant (n.s.); progression-free survival (PFS) = 0% vs. 17%, P = n.s.]. Patients with standard-risk cytogenetics (n = 65) showed a better prognosis when associated with a lower number of circulating PCs (PC < 41 vs. PC ≥ 41: OS = 62% vs. 24%, P = 0·008; PFS = 48% vs. 21%, P = 0·001). Multivariate analysis on the subgroup with standard-risk cytogenetics confirmed that the co-presence of circulating PCs ≥ 41, older age, Durie-Salmon stage >I and lack of maintenance adversely affected PFS, while OS was adversely affected only by lactate dehydrogenase, older age and lack of maintenance. Our results indicate that the quantification of circulating PCs by a simple two-colour FC analysis can provide useful prognostic information in newly diagnosed MM patients with standard-risk cytogenetics.

Multiparameter flow cytometry provides independent prognostic information in patients with suspected myelodysplastic syndromes: A study on 804 patients

Diagnosis of myelodysplastic syndromes (MDS) relies on well-defined cytomorphologic criteria but is challenging in a significant number of patients. The detection of aberrant antigen expression by multiparameter flow cytometry (MFC) is considered a promising tool to improve MDS diagnostics. We prospectively analyzed 804 unselected patients sent with suspected MDS for correlation of MFC findings with overall survival (OS) in the context of cytomorphologic and cytogenetic findings. Patients with evidence of MDS by MFC had a significantly worse OS as compared to those without (OS at 2 years, 71.2% vs. 89.4%; P<0.001). The number of aberrantly expressed antigens as a continuous variable was significantly associated with OS [P<0.001, hazards ratio (HR): 1.19 per additional aberrantly expressed antigen]. Multivariate analysis proved a diagnosis of MDS by MFC to be independently associated with OS (P=0.050; HR: 1.42). Furthermore, a diagnosis of MDS by MFC was related to inferior survival within all three cytomorphologically defined subgroups, i.e., proven MDS (median OS, 45.4 vs. 52.8 months, P<0.001), suspected MDS (2-year-OS, 75.0% vs. 82.8%; P=0.062), and MDS excluded (2-year-OS, 63.5% vs. 92.8%, P=0.020). Our data clearly demonstrate that, in the assessment of cytopenic patients with suspected MDS, a diagnosis of MDS by MFC is independently associated with OS, which had been shown in previous studies for today's standard diagnostic parameters cytomorphology and cytogenetics. MFC may, therefore, be considered an additional tool in the diagnostic workup of patients with suspected MDS.

AML with gain of chromosome 8 as the sole chromosomal abnormality (+8sole) is associated with a specific molecular mutation pattern including ASXL1 mutations in 46.8% of the patients

Trisomy 8 is the most frequent cytogenetically gained aberration in AML. We compared 79 adult de novo AML with trisomy 8 as the sole cytogenetic abnormality (+8sole) to 511 normal karyotype AML patients (NK). +8sole patients were older (p=0.013), presented lower WBC counts (p=0.010), harbored more often ASXL1 mutations (p<0.001) and RUNX1 mutations (p=0.009), but less frequent FLT3-ITD (p=0.038), NPM1 mutations (p<0.001) and double-mutated CEBPA (p=0.038) than NK patients. No prognostic difference was found between +8sole and NK. With respect to genetic stability we found +8sole was instable, and molecular markers were either stable or gained in number and diversity.

Mosaike in der Tumorzytogenetik

Eine Tumorerkrankung stellt, bezogen auf den Gesamtorganismus, per definitionem ein Mosaik dar. Zusätzlich sind die meisten Tumoren, für sich betrachtet, Mosaike. Dieser Mosaikstatus wird üblicherweise als intratumorale Heterogenität bezeichnet und ist ein wesentlicher Faktor, der sowohl Relevanz für die Diagnostik als auch für die therapeutischen Strategien hat. Um die genetischen Veränderungen eines Tumors analysieren zu können, muss im Rahmen der Diagnostik sichergestellt werden, dass eine ausreichende Anzahl an Tumorzellen ausgewertet werden kann und nicht lediglich das normale Gewebe betrachtet wird. Dieses wird in der Diagnostik bei den verschiedenen Neoplasien mit unterschiedlichen Vorgehensweisen in Abhängigkeit von den verwendeten diagnostischen Methoden und der Art der Neoplasie erreicht. Zur Anwendung kommen Methoden, die die malignen Zellen anreichern und diese gezielt zur Proliferation stimulieren, oder die Methode wird mit einer ausreichenden Sensitivität durchführt, um auch kleine Klone erfassen zu können.

Diagnostic utility of multiprobe fluorescence in situ hybridization assay for detecting cytogenetic aberrations in acute leukemia

BACKGROUND

Specific cytogenetic aberrations detected by conventional karyotyping or FISH play a major role in the diagnosis, prognosis, and treatment of patients with acute leukemia. The FISH technique enhances the capacity of conventional karyotyping to detect subtle chromosomal aberrations. Multiprobe FISH assay (Cytocell, UK) can hybridize multiple probes to a single slide, thereby increasing the detection rate of cytogenetic aberrations. This study aimed to evaluate multiprobe FISH in detecting cytogenetic abnormalities in acute leukemia.

METHODS

Thirty newly diagnosed acute leukemia patients who attended the hematology clinic at Dong-A University Hospital from October 2008 to October 2012 were enrolled in the study. The multiprobe FISH results were compared with those of G-banding.

RESULTS

Multiprobe FISH detected the chromosomal aberrations identified by G-banding, as well as additional aberrations in 6 of 30 (20.0%) cases, which included ETV6/RUNX1 translocation, p16 deletion, TP53 deletion, and IGH break-apart.

CONCLUSIONS

The multiprobe FISH assay was a more sensitive and reliable technique compared with G-banding. It was also more cost-effective and yielded faster results.

High number of additional genetic lesions in acute myeloid leukemia with t(8;21)/RUNX1-RUNX1T1: frequency and impact on clinical outcome

t(8;21)/RUNX1-RUNX1T1-positive acute myeloid leukemia (AML) is prognostically favorable; however, outcome is heterogeneous. We analyzed 139 patients with t(8;21)/RUNX1-RUNX1T1-positive AML (de novo: n=117; therapy-related: n=22) to determine frequency and prognostic impact of additional genetic abnormalities. All patients were investigated for mutations (mut) in ASXL1, FLT3, KIT, NPM1, MLL, IDH1, IDH2, KRAS, NRAS, CBL and JAK2. Sixty-nine of 139 cases (49.6%) had 1 mutation in addition to RUNX1-RUNX1T1, and 23/139 (16.5%) had ⩾2 additional mutations. Most common were KITmut (23/139; 16.5%), NRASmut (18/139; 12.9%) and ASXL1mut (16/139; 11.5%). FLT3-ITD, FLT3-TKDmut, CBLmut, KRASmut, IDH2mut and JAK2mut were found in 2.9-5.0%. Additional chromosomal abnormalities (ACAs) were found in 97/139 (69.8%). Two-year overall survival (OS) was 73.4% in 111 intensively treated patients. KITD816mut negatively impacted on OS in de novo AML (2-year OS: 59.1% vs 82.0%, P=0.03), ASXL1mut on EFS (de novo AML: 20% vs 59.1%, P=0.011; total cohort: 28.6% vs 56.7%, P=0.021). Sex chromosome loss was favorable (2-year EFS: 66.9% vs 43.0%, P=0.031), whereas +8 was adverse on EFS (2-year EFS: 26.7% vs 55.9%, P=0.02). In conclusion, t(8;21)/RUNX1-RUNX1T1-positive AML shows a high frequency of additional genetic alterations. Investigation for KITD816 and ASXL1mut combined with investigation of ACAs is recommended in t(8;21)/RUNX1-RUNX1T1-positive AML because of the prognostic significance of these parameters.

Investigation of 305 patients with myelodysplastic syndromes and 20q deletion for associated cytogenetic and molecular genetic lesions and their prognostic impact

In patients with myelodysplastic syndromes (MDS), sole 20q deletion [del(20q)] is a recurrent favourable abnormality. We studied additional molecular and cytogenetic lesions and their prognostic impact in 305 MDS patients with del(20q) (229 males/76 females; 29-90 years). All patients were investigated by cytomorphology and chromosome banding analysis (CBA), subsets by fluorescence in situ hybridization, molecular mutation screening, and array comparative genomic hybridization (aCGH). By aCGH (n = 30), the minimal common deleted region (CDR) was flanked by PTPRT (20q13·11) and EYA2 (20q13·12). 210 (68·9%) patients had 'early MDS' without blast increase, 95 (31·1%) 'advanced' MDS with blast increase (5-19%). Additional chromosomal abnormalities (ACAs) were detected in 88/305 (28·9%) patients. Patients with advanced MDS more frequently had ACAs (P = 0·003) and had a higher mean number of ACAs (P = 0·020) and of molecular mutations (P = 0·060). Spliceosome mutations were frequent (U2AF1: n = 31/155; 20·0%; SRSF2: n = 31/159; 19·5%; SF3B1mut: n = 8/159; 5·0%). ASXL1mut (25/153; 16·3%) were associated with advanced MDS (P = 0·001). Presence of ≥3 ACAs (P = 0·003) and ASXL1mut (P = 0·002) were associated with worse 2-year survival. In conclusion, the cytogenetic subgroup of MDS with del(20q) has a good prognosis but may be further subclassified by additional cytogenetic and molecular lesions. U2AF1mut is overrepresented in MDS with del(20q), and ASXL1mut is prognostically adverse.

Array-CGH as an adjuvant tool in cytogenetic diagnosis of pediatric MDS and JMML

Myelodysplastic syndromes (MDS) and juvenile myelomonocytic leukemia (JMML) are rare clonal hematopoietic diseases presented in the childhood. Both diseases exhibit abnormal karyotype and/or monosomy of chromosome 7 in a subgroup of patients. We screened for copy number variations (CNVs) by array-comparative genomic hybridization (aCHG) the DNA from bone marrow of six MDS and four JMML pediatric patients. Array-CGH analysis identified five cases (50%) with monosomy 7, disclosing the chromosome 7 monosomy in two patients whose samples could not be evaluated by other methods. We identified CNVs in six patients, one of which displayed loss of LMO2, an oncogene that plays a central role in hematopoietic development. Our results suggest that array-CGH is a reliable and accurate technique to identify genomic alterations in MDS and JMML.

[Current diagnostic requirements in chronic myeloid leukemia]

In patients with chronic myeloid leukemia, high-quality diagnostics is of paramount importance for the surveillance of treatment efficacy. The availability of new tyrosine kinase inhibitors providing more rapid and deeper responses requires the employment of standardized and highly sensitive diagnostic methods to ensure optimal monitoring of the patients. This review presents the current international diagnostic standards and the certified laboratories in Austria.

Morphology, cytogenetics and classification of MDS

Myelodysplastic syndromes are heterogeneous bone marrow diseases with a variable pathogenetic background. Cytomorphological alterations in peripheral blood films as well as bone marrow aspirates and histological findings in trephine biopsies result from cytogenetic and molecular abnormalities, epigenetic dysregulation and immune dysfunction and are key elements for setting the diagnosis of MDS. Whereas diagnosis can be made quite easily in advanced MDS this is much more difficult in early MDS, especially in cases with cytopenias or dysplasias of uncertain significance (ICUS and IDUS). Recommendations, illustrated by case reports for a stepwise annealing to the final diagnosis and exclusion of differential diagnoses are given. Furthermore, the problem of correct counting and identification of blasts is covered and features defining dysplasia in all three cell lineages are recapitulated thoroughly. Histopathology is not mandatory but has a distinct diagnostic and prognostic value especially in cases with hypoplasia or fibrosis and when the TP53 mutational status is of relevance. In up to 70% of patients with MDS clonal chromosome abnormalities can be identified which have a high impact on setting the correct diagnosis and estimation of prognosis. Incidence, type, molecular background and clinical relevance of distinct anomalies as well as cytogenetic subgroups are presented in detail and the development of the new cytogenetic prognostic scoring system as part of the IPSS-R is explained. The value of FISH-Analysis as a complementary tool for chromosome analysis in MDS is demonstrated with special emphasis on the possibility to perform frequent cytogenetic monitoring by CD34-FISH examination of peripheral blood. Finally the evolution of MDS-classification systems from FAB to WHO with a critical discussion of their shortcomings like degree of dysplasia, blast thresholds, inclusion/exclusion of CMML, and the lack of dynamic information is presented.

6q deletion detected by fluorescence in situ hybridization using bacterial artificial chromosome in chronic lymphocytic leukemia

Deletions of the long arm of chromosome 6 are known to occur at relatively low frequency (3-6%) in chronic lymphocytic leukemia (CLL), and they are more frequently observed in 6q21. Few data have been reported regarding other bands on 6q involved by cytogenetic alterations in CLL. The cytogenetic study was performed in nuclei and metaphases obtained after stimulation with a combination of CpG-oligonucleotide DSP30 and interleukin-2. Four bacterial artificial chromosome (BAC) clones mapping regions in bands 6q16, 6q23, 6q25, 6q27 were used as probes for fluorescence in situ hybridization in 107 CLL cases in order to analyze the occurrence and localization of 6q aberrations. We identified 11 cases (10.2%) with 6q deletion of 107 patients studied with CLL. The trends of survival curves and the treatment-free intervals (TFI) of patients with deletion suggest a better outcome than the other cytogenetic risk groups. We observed two subgroups with 6q deletion as the sole anomaly: two cases with 6q16 deletion, and three cases with 6q25.2-27 deletion. There were differences of age, stage, and TFI between both subgroups. By using BAC probes, we observed that 6q deletion has a higher frequency in CLL and is linked with a good prognosis. In addition, it was observed that the deletion in 6q16 appears to be the most frequent and, if present as the only abnormality, it could be associated with a most widespread disease.

SETBP1 mutations occur in 9% of MDS/MPN and in 4% of MPN cases and are strongly associated with atypical CML, monosomy 7, isochromosome i(17)(q10), ASXL1 and CBL mutations

Chronic myeloid malignancies are categorized to the three main categories myeloproliferative neoplasms (MPNs), myelodysplastic syndromes (MDSs) and MDS/MPN overlap. So far, no specific genetic alteration profiles have been identified in the MDS/MPN overlap category. Recent studies identified mutations in SET-binding protein 1 (SETBP1) as novel marker in myeloid malignancies, especially in atypical chronic myeloid leukemia (aCML) and related diseases. We analyzed SETBP1 in 1 130 patients with MPN and MDS/MPN overlap and found mutation frequencies of 3.8% and 9.4%, respectively. In particular, there was a high frequency of SETBP1 mutation in aCML (19/60; 31.7%) and MDS/MPN unclassifiable (MDS/MPN, U; 20/240; 9.3%). SETBP1 mutated (SETBP1mut) patients showed significantly higher white blood cell counts and lower platelet counts and hemoglobin levels than SETBP1 wild-type patients. Cytomorphologic evaluation revealed a more dysplastic phenotype in SETBP1mut cases as compared with wild-type cases. We confirm a significant association of SETBP1mut with -7 and isochromosome i(17)(q10). Moreover, SETBP1mut were strongly associated with ASXL1 and CBL mutations (P<0.001 for both) and were mutually exclusive of JAK2 and TET2 mutations. In conclusion, SETBP1mut add an important new diagnostic marker for MDS/MPN and in particular for aCML.

Serial assessment of suspected myelodysplastic syndromes: significance of flow cytometric findings validated by cytomorphology, cytogenetics, and molecular genetics

The significance of flow cytometry indicating myelodysplasia without proof of myelodysplasia by cytomorphology remains to be clarified. We evaluated follow-up analyses in 142 patients analyzed in parallel by flow cytometry, cytomorphology and cytogenetics for suspected myelodysplasia without proof of myelodysplasia by cytomorphology. At initial assessment, flow cytometry indicated myelodysplasia in 64 of 142 (45.1%) patients. In 9 of 142 (6.3%) patients, cytogenetics revealed aberrant karyotypes at first evaluation that were found in 5 of 64 (7.8%) patients rated with myelodysplasia by flow cytometry. The remaining 133 patients without proof of myelodysplasia by cytomorphology and with normal karyotype underwent follow-up analyses that confirmed myelodysplasia by cytomorphology, cytogenetics or molecular genetics in 47 (35.3%) after a median interval of nine months (range 1-53 months). As far as initial flow cytometry results are concerned, this applied to 30 of 59 (50.1%) with myelodysplasia, 10 of 42 (23.8%) with "possible myelodysplasia" (minor antigen aberrancies only) and 7 of 32 (21.9%) without myelodysplasia (P=0.004). Notably, in these latter 7 patients, flow cytometry results changed at follow up to "possible myelodysplasia" (n=4) and "myelodysplasia" (n=2). These data argue in favor of including flow cytometry along with cytomorphology, cytogenetics and molecular genetics to diagnose myelodysplasia, and suggest a closer monitoring of patients with myelodysplasia-typical aberrant antigen expression found by flow cytometry.

Evaluation of flow cytometric assessment of myeloid nuclear differentiation antigen expression as a diagnostic marker for myelodysplastic syndromes in a series of 269 patients

BACKGROUND

Myeloid nuclear differentiation antigen (MNDA) is expressed in myelomonocytic cells with highest levels in mature granulocytes and monocytes. It is suggested to be expressed more weakly in patients with myelodysplastic syndromes (MDS). The analysis of MNDA therefore may improve diagnostic capabilities of multiparameter flow cytometry (MFC) in MDS.

METHODS

We used MFC for detection of MNDA expression in 269 patients with suspected or known MDS, acute myeloid leukemia (AML) or chronic myelomonocytic leukemia (CMML), cytopenia of unknown cause or without malignancy (negative controls). Results were compared with the diagnoses revealed by cytomorphology (CM) and cytogenetics (CG).

RESULTS

Percentages of granulocytes and monocytes with diminished MNDA expression (dimG and dimM) were higher in patients with MDS (mean ± SD, 20% ± 20%, P < 0.001 and 31% ± 24%, P < 0.001) and AML (27% ± 27%, P = 0.007 and 45% ± 31%, P = 0.001) diagnosed by CM, vs. patients without MDS (8% ± 10% and 16% ± 11%), respectively. Significant differences were also found for mean fluorescence intensity (MFI) of MNDA in monocytes which was lower in MDS (mean ± SD, 71 ± 36, P = 0.004) and AML (55 ± 39, P < 0.001) vs. no MDS samples (85 ± 28), respectively. Within patients with MDS, cases with cytogenetic aberrations showed a trend to higher %dimG (24% ± 18%, P = 0.083) compared with those without (16% ± 21%). Cut-off values for %dimG (12%) and %dimM (22%) as well as for MFI in monocytes (72) were defined capable of discriminating between MDS and non-MDS.

CONCLUSION

MNDA expression in bone marrow cells can be assessed reliably by MFC and may facilitate evaluation of dyspoiesis when added to a standard MDS MFC panel.

FOXP1 and PAX5 are rare but recurrent translocations partners in acute lymphoblastic leukemia

Here, we report the case of a 57-year-old man, who was diagnosed with B-cell acute lymphoblastic leukemia (B-ALL). His diagnostic workup identified a translocation t(3;9)(p13;p13). This is the fifth case reported to date that involved the forkhead box P1 gene (FOXP1) and paired box gene 5 (PAX5). The PAX5-FOXP1 translocation is a nonrandom aberration, which is recurrent in both childhood and in adult B-ALL, and may contribute to leukemogenesis by blocking differentiation of hematopoietic cells into mature B-cells.

Cytogenetic follow-up by karyotyping and fluorescence in situ hybridization: implications for monitoring patients with myelodysplastic syndrome and deletion 5q treated with lenalidomide

In patients with low and intermediate risk myelodysplastic syndrome and deletion 5q (del(5q)) treated with lenalidomide, monitoring of cytogenetic response is mandatory, since patients without cytogenetic response have a significantly increased risk of progression. Therefore, we have reviewed cytogenetic data of 302 patients. Patients were analyzed by karyotyping and fluorescence in situ hybridization. In 85 patients, del(5q) was only detected by karyotyping. In 8 patients undergoing karyotypic evolution, the del(5q) and additional chromosomal aberrations were only detected by karyotyping. In 3 patients, del(5q) was only detected by fluorescence in situ hybridization, but not by karyotyping due to a low number of metaphases. Karyotyping was significantly more sensitive than fluorescence in situ hybridization in detecting the del(5q) clone. In conclusion, to optimize therapy control of myelodysplastic syndrome patients with del(5q) treated with lenalidomide and to identify cytogenetic non-response or progression as early as possible, fluorescence in situ hybridization alone is inadequate for evaluation. Karyotyping must be performed to optimally evaluate response.

The European LeukemiaNet: achievements and perspectives

The only way to cure leukemia is by cooperative research. To optimize research, the European LeukemiaNet integrates 105 national leukemia trial groups and networks, 105 interdisciplinary partner groups and about 1,000 leukemia specialists from 175 institutions. They care for tens of thousands of leukemia patients in 33 countries across Europe. Their ultimate goal is to cure leukemia. Since its inception in 2002, the European LeukemiaNet has steadily expanded and has unified leukemia research across Europe. The European LeukemiaNet grew from two major roots: 1) the German Competence Network on Acute and Chronic Leukemias; and 2) the collaboration of European Investigators on Chronic Myeloid Leukemia. The European LeukemiaNet has improved leukemia research and management across Europe. Its concept has led to funding by the European Commission as a network of excellence. Other sources (European Science Foundation; European LeukemiaNet-Foundation) will take over when the support of the European Commission ends.

Clinical utility of FISH analysis in addition to G-banded karyotype in hematologic malignancies and proposal of a practical approach

Background

Fluorescence in situ hybridization (FISH) analysis can provide important information in the management of patients with hematologic malignancies. However, FISH performed in addition to G-banded karyotype can be labor-intensive and expensive. The aim of this study was to evaluate whether FISH gives additional information in the setting of adequate conventional cytogenetics in cases of hematologic malignancies.

Methods

Bone marrow aspirates were obtained from 135 patients at diagnosis (56 AML, 32 MDS, 20 ALL, and 27 MM) between 2005 and 2010. Interphase FISH was performed using the following probes: BCR/ABL1, AML1/ETO, PML/RARA, CBFB, MLL, EGR1, CEP8, and D7S486 for AML; CEP8, D20S108, EGR1, and D7S486 for MDS; BCR/ABL1, MLL, CDKN2A (p16), ETV6, and 6q21/c-myc for ALL; IgH, TP53, D13S25, IgH/CCND1, IgH/MAF, IgH/FGFR3, and 1q21/8p21 for MM. We compared the results of FISH with the corresponding aberrations identified by G-banded karyotype.

Results

Additional genetic aberrations detected by FISH (which were not identified by G-banded karyotype) were 4%, 9%, 50%, and 67% in AML, MDS, ALL, and MM, respectively. In ALL, CDKN2A and ETV6 FISH revealed additional genetic aberrations in 33% and 28% of cases, respectively. In MM, FISH was of benefit in detecting IgH, D13S25, TP53, and 1q21 rearrangements, not detected by G-banded karyotype (31%, 36%, 20%, and 40%, respectively).

Conclusion

These results suggest that performing FISH in addition to G-banded karyotype may contribute little additional genetic information in AML and MDS, whereas routine FISH analysis appears to be an efficient screening method in ALL and MM.

Telomere dysfunction-induced foci arise with the onset of telomeric deletions and complex chromosomal aberrations in resistant chronic lymphocytic leukemia cells

In somatic cells, eroded telomeres can induce DNA double-strand break signaling, leading to a form of replicative senescence or apoptosis, both of which are barriers to tumorigenesis. However, cancer cells might display telomere dysfunctions which in conjunction with defects in DNA repair and apoptosis, enables them to circumvent these pathways. Chronic lymphocytic leukemia (CLL) cells exhibit telomere dysfunction, and a subset of these cells are resistant to DNA damage-induced apoptosis and display short telomeres. We show here that these cells exhibit significant resection of their protective telomeric 3' single-stranded overhangs and an increased number of telomere-induced foci containing gammaH2AX and 53BP1. Chromatin immunoprecipitation and immunofluorescence experiments demonstrated increased levels of telomeric Ku70 and phospho-S2056-DNA-PKcs, 2 essential components of the mammalian nonhomologous end-joining DNA repair system. Notably, these CLL cells display deletions of telomeric signals on one or 2 chromatids in parallel with 11q22 deletions, or with 13q14 deletions associated with another chromosomal aberration or with a complex karyotype. Taken together, our results indicate that a subset of CLL cells from patients with an unfavorable clinical outcome harbor a novel type of chromosomal aberration resulting from telomere dysfunction.

A new reliable fluorescence in situ hybridization method for identifying multiple specific cytogenetic abnormalities in acute myeloid leukemia

The usefulness of the new Chromoprobe Multiprobe AML Panel was evaluated in 80 patients with acute myeloid leukemia (AML) in parallel with conventional cytogenetics. We observed a high concordance using both methods, but the panel was very useful in the detection of an inv(16)(p13q22), a cryptic t(15;17)(q22;q21), and a cryptic deletion of the CBFbeta allele not detected with cytogenetics. Moreover, in six of nine patients (67%) without metaphases or with non-evaluable chromosomes, the panel identified three MLL rearrangements, two monosomy 7, one of them also with del(5q), and one inv(16)(p13q22). Our results indicate that the multiprobe panel can be used as a complementary technique for detection of the most important chromosomal abnormalities in AML using small quantities of sample in only one hybridization experiment. It is also capable of reallocating cases without metaphases or with non-evaluable chromosomes in the appropriate cytogenetic risk group.

Diagnostic tools in the indications for allogeneic stem cell transplantation in myelodysplastic syndromes

The rates of allogeneic stem cell transplantation (SCT) to treat the myelodysplastic syndromes (MDS) is continually increasing. However, given the growing arsenal of therapeutic options in parallel to deeper insight into the heterogeneity of this disorder, determining the indications for SCT in MDS remains a difficult task. The International Prognostic Scoring System (IPSS) serves as a guideline for therapeutic decisions, but many aspects (eg, interpretation of rare cytogenetic abnormalities, combinations of chromosomal alterations and/or molecular markers, variant clinical courses within distinct biological subgroups) remain the subject of continuous investigation. In an effort to achieve a more well-differentiated risk categorization, attempts have been made to perform a more detailed cytogenetic categorization, and the use of various fluorescein in situ hybridization (FISH) techniques has improved the description of aberrations. Multicenter initiatives have standardized multiparameter flow cytometry techniques for diagnosis of MDS. In advanced MDS, screening for molecular mutations can identify cases with a high transformation risk. Finally, the new World Health Organization classification system provides a more homogenous morphological categorization of MDS compared with the former French-American-British system. Consequently, in the near future, risk stratification in MDS might incorporate additional diagnostic tools and categorization systems aimed at improving the timing and indication for SCT in this complex disorder.

Meeting report: Vienna 2008 Workshop of the German-Austrian Working Group for Studying Prognostic Factors in Myelodysplastic Syndromes

Criteria, scoring systems, and treatment algorithms for myelodysplastic syndromes (MDS) have been updated repeatedly in recent years. This apparently results from increased awareness and early recognition of the disease, an increasing number of new diagnostic and prognostic markers and tools, and new therapeutic options that may change the course and thus prognosis in MDS. To address these challenges and to create useful new diagnostic and prognostic parameters and scores, the German-Austrian Working Group for Studying Prognostic Factors in MDS was established in 2003 and later was extended to centers in Switzerland (D-A-CH group). In addition, the group cooperates with the European LeukemiaNet, the MDS Foundation, and other national and international working groups in order to improve diagnosis and prognostication. The current article represents a meeting report from the latest workshop organized by the group in Vienna in October 2008.