Is FISH a relevant prognostic tool in myelodysplastic syndromes with a normal chromosome pattern on conventional cytogenetics? A study on 57 patients

Measurable (Minimal) Residual Disease in Myelodysplastic Neoplasms (MDS): Current State and Perspectives

Myelodysplastic Neoplasms (MDS) have been traditionally studied through the assessment of blood counts, cytogenetics, and morphology. In recent years, the introduction of molecular assays has improved our ability to diagnose MDS. The role of Measurable (minimal) Residual Disease (MRD) in MDS is evolving, and molecular and flow cytometry techniques have been used in several studies. In this review, we will highlight the evolving concept of MRD in MDS, outline the various techniques utilized, and provide an overview of the studies reporting MRD and the correlation with outcomes.

A Single-Run Next-Generation Sequencing (NGS) Assay for the Simultaneous Detection of Both Gene Mutations and Large Chromosomal Abnormalities in Patients with Myelodysplastic Syndromes (MDS) and Related Myeloid Neoplasms

Simple Summary

Chromosomal abnormalities and somatic mutations are found in patients with myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) in around 50–80% of cases. The identification of these alterations is important for the accurate diagnosis and prognostic classification of these patients. Often, an apparently normal or failed karyotype might lead to an inadequate estimation of the prognostic risk, and several strategies should be combined to solve these cases. The aim of this study was to introduce a novel next-generation sequencing (NGS)-based strategy for the simultaneous detection of all the clinically relevant genetic alterations associated with these disorders. We validated this approach on a large cohort of patients by comparing our findings with those obtained with standard-of-care methods (i.e., karyotype and SNP-arrays). We show that our platform represents a significant improvement on current strategies in defining diagnosis and risk stratification of patients with MDS and myeloid-related disorders.

Abstract

Myelodysplastic syndromes (MDS) and myelodysplastic/myeloproliferative neoplasms are clonal disorders that share most of their cytogenetic and molecular alterations. Despite the increased knowledge of the prognostic importance of genetics in these malignancies, next-generation sequencing (NGS) has not been incorporated into clinical practice in a validated manner, and the conventional karyotype remains mandatory in the evaluation of suspected cases. However, non-informative cytogenetics might lead to an inadequate estimation of the prognostic risk. Here, we present a novel targeted NGS-based assay for the simultaneous detection of all the clinically relevant genetic alterations associated with these disorders. We validated this platform in a large cohort of patients by performing a one-to-one comparison with the lesions from karyotype and single-nucleotide polymorphism (SNP) arrays. Our strategy demonstrated an approximately 97% concordance with standard clinical assays, showing sensitivity at least equivalent to that of SNP arrays and higher than that of conventional cytogenetics. In addition, this NGS assay was able to identify both copy-neutral loss of heterozygosity events distributed genome-wide and copy number alterations, as well as somatic mutations within significant driver genes. In summary, we show a novel NGS platform that represents a significant improvement to current strategies in defining diagnosis and risk stratification of patients with MDS and myeloid-related disorders.

Fluorescence in Situ Hybridization (FISH) Utility for Risk Score Assessment in Patients With MDS With Normal Metaphase Karyotype

BACKGROUND

Cytogenetic profile is an essential parameter in myelodysplastic syndromes (MDS) risk stratification by both International Prognostic Symptom Score (IPSS) and Revised (R)-IPSS. Almost one-half of patients with MDS have normal cytogenetics by metaphase karyotype. Here we report the yield of MDS fluorescence in situ hybridization (FISH) panel detecting cytogenetic abnormalities in these patients and its impact on risk stratification.

PATIENTS AND METHODS

Among patients with normal metaphase karyotype, we assessed those patients who had cytogenetic abnormalities detected by an MDS FISH panel, which included probes for del (5), del (7), del (20), trisomy 8, and del (17p). Risk stratification was calculated by both IPSS and R-IPSS.

RESULTS

Of 1600 patients with MDS with normal metaphase karyotype, 53 (3%) patients had cytogenetic abnormality detected by MDS FISH panel. Integrating the MDS FISH panel cytogenetics (IPSS + FISH restaging) resulted in upstaging the score, where 53% of low-risk IPSS were upstaged to intermediate (int)-1, 56% of int-1 were upstaged to int-2, and 78% of int-2 were upstaged to high risk. Based on the R-IPSS, 61% of very low-risk patients, all low-risk patients, 92% of intermediate-risk patients, and 50% of high-risk patients with FISH abnormalities were upstaged, respectively.

CONCLUSION

The yield of MDS FISH panel detecting cytogenetic abnormalities in patients with normal karyotype by G-banding is low and may not warrant ordering the panel in all patients. Among the 3% of patients with normal karyotype who had cytogenetic abnormality detected by FISH, the risk score assignment by IPSS and R-IPSS was upstaged.

Comparative assessment of conventional chromosomal analysis and fluorescence in situ hybridization in the evaluation of suspected myelodysplastic syndromes: A single institution experience

Background:

Myelodysplastic syndromes (MDSs) are a heterogeneous group of clonal hematopoietic neoplasms, roughly half of which harbor cytogenetic abnormalities with diagnostic, prognostic, and therapeutic significance. Fluorescence in situ hybridization (FISH) for the most commonly seen abnormalities (5/5q, –7/7q, +8, and –20/20q–) is routinely performed alongside conventional cytogenetics (CC) in the evaluation of suspected MDS despite conflicting reports of its relative contribution compared to CC alone.

Objectives:

To assess the additional diagnostic and prognostic value of performing concurrent FISH versus CC alone in cases of suspected MDS.

Materials and Methods:

A total of 127 bone marrow samples submitted to our cytogenetic laboratory with a presumptive diagnosis of MDS were evaluated by concurrent CC and an MDS FISH panel.

Results:

CC was used as the gold standard method with 100% sensitivity in detecting suspected MDS-associated cytogenetic abnormalities. FISH alone had a sensitivity of 76%, whereas CC alone achieved a sensitivity of 97%. The addition of FISH did not change the diagnosis nor change the Revised International Prognostic Scoring System score in any patient. Moreover, in 12 cases identified as positive by both CC and FISH, CC identified multiple chromosomal aberrations of clinical significance not interrogated by the FISH probe panel.

Conclusion:

CC alone is sufficiently sensitive in detecting suspected MDS-associated cytogenetic abnormalities that influence clinical decision-making. Routine FISH testing does not provide a significant increase in test sensitivity when an adequate karyotype is obtained. Therefore, FISH testing is best reserved for suspected MDS cases lacking sufficient metaphases.

Is fluorescence in-situ hybridization sufficient in patients with myelodysplastic syndromes and insufficient cytogenetic testing?

Chromosome banding analysis (CBA) in myelodysplastic syndromes (MDS) remains the 'gold standard' for identification of chromosomal abnormalities, while interphase fluorescence in-situ hybridization (I-FISH) is mainly used to complement CBA. This study, retrospectively, evaluated CBA and I-FISH results in 600 patients with suspected MDS and determined the effect of CBA/FISH reallocation on IPSS-R. Our result demonstrated that in 7/586 (1.2%) patients with satisfactory karyotype, I-FISH provided additional information. In 25/453 (5.5%) of the patients with normal I-FISH, CBA detected chromosomal abnormalities, and in 68/147 (46%) of the patients with abnormal I-FISH, CBA detected additional chromosomal aberrations. When 5q- aberration was alone or accompanied by additional abnormalities by I-FISH, CBA revealed a complex karyotype (16/25;64%, 35/43;81%, respectively). Our results suggest that in cases of karyotype failure, if I-FISH is used alone, patients are at risk of being misclassified into the wrong cytogenetic risk groups and a repeat sample for CBA should be attempted.

Evaluation of the utility of peripheral blood vs bone marrow in karyotype and fluorescence in situ hybridization for myelodysplastic syndrome diagnosis

OBJECTIVE

To clear the role of peripheral blood as a substitution for bone marrow in myelodysplastic syndrome and to evaluate the concordance between peripheral blood and bone marrow using karyotype and fluorescence in situ hybridization (FISH) methods.

METHODS

We examined 35 bone marrow (BM) and peripheral blood (PB) samples from myelodysplastic syndrome (MDS) patient using karyotype and FISH. Karyotype method for BM and PB samples performed using the standard protocol with an exception for peripheral blood in which growth factor for cultivation was not used. FISH testing was performed using a panel of MDS-associated probes to detect 20q12, 20qter, 5q31, 5q33, 5p15 and chromosome 7 and 8 centromeres.

RESULTS

Our results showed karyotypes of BM and PB are concordant in 74% of cases, while about 53% of these concordances were achieved from cases with normal karyotypes. However, the results of BM FISH were completely concordant with PB FISH.

CONCLUSION

Although peripheral blood karyotype is not trustworthy for MDS diagnosis, examining peripheral blood, using the FISH method, could be useful for clinical monitoring.

Prognostic classification of MDS is improved by the inclusion of FISH panel testing with conventional cytogenetics

Cytogenetics is a critical independent prognostic factor in myelodysplastic syndromes (MDS). Conventional cytogenetics (CC) and Fluorescence in situ hybridization (FISH) Panel Testing are extensively used for the prognostic stratification of MDS, although the FISH test is not yet a bona fide component of the International Prognostic Scoring System (IPSS). The present study compares the utility of CC and FISH to detect chromosomal anomalies and in prognostic categorization. GTG-Banding and FISH Panel Testing specifically for -5/-5q, -7/-7q, +8 and -20q was performed on whole blood or bone marrow samples from 136 patients with MDS. Chromosomal anomalies were found in 40 cases by CC, including three novel translocations. FISH identified at least one anomaly in 54/136 (39.7%) cases. More than one anomaly was found in 18/54 (33.3%) cases, therefore, overall FISH identified 75 anomalies of which 32 (42.6%) were undetected by CC. FISH provided additional information in cases with CC failure and in cases with a normal karyotype. Further, in ten cases with an abnormal karyotype, FISH could identify additional anomalies, increasing the number of abnormalities per patient. Although CC is the gold standard in the cytogenetic profiling of MDS, FISH has proven to be an asset in identifying additional abnormalities. The number of anomalies per patient can predict the prognosis in MDS and hence, FISH contributed towards prognostic re-categorization. The FISH Panel testing should be used as an adjunct to CC, irrespective of the adequacy of the number of metaphases in CC, as it improves the prognostic classification of MDS.

Proposed minimal diagnostic criteria for myelodysplastic syndromes (MDS) and potential pre-MDS conditions

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of myeloid neoplasms characterized by peripheral cytopenia, dysplasia, and a variable clinical course with about 30% risk to transform to secondary acute myeloid leukemia (AML). In the past 15 years, diagnostic evaluations, prognostication, and treatment of MDS have improved substantially. However, with the discovery of molecular markers and advent of novel targeted therapies, new challenges have emerged in the complex field of MDS. For example, MDS-related molecular lesions may be detectable in healthy individuals and increase in prevalence with age. Other patients exhibit persistent cytopenia of unknown etiology without dysplasia. Although these conditions are potential pre-phases of MDS they may also transform into other bone marrow neoplasms. Recently identified molecular, cytogenetic, and flow-based parameters may add in the delineation and prognostication of these conditions. However, no generally accepted integrated classification and no related criteria are as yet available. In an attempt to address this challenge, an international consensus group discussed these issues in a working conference in July 2016. The outcomes of this conference are summarized in the present article which includes criteria and a proposal for the classification of pre-MDS conditions as well as updated minimal diagnostic criteria of MDS. Moreover, we propose diagnostic standards to delineate between ´normal´, pre-MDS, and MDS. These standards and criteria should facilitate diagnostic and prognostic evaluations in clinical studies as well as in clinical practice.

Myelodysplastic syndromes: advantages of a combined cytogenetic and molecular diagnostic workup

In this study we present a new diagnostic workup for the myelodysplastic syndromes (MDS) including FISH, aCGH, and somatic mutation assays in addition to the conventional cytogenetics (CC). We analyzed 61 patients by CC, FISH for chromosome 5, 7, 8 and PDGFR rearrangements, aCGH, and PCR for ASXL1, EZH2, TP53, TET2, RUNX1, DNMT3A, SF3B1 somatic mutations. Moreover, we quantified WT1 and RPS14 gene expression levels, in order to find their possible adjunctive value and their possible clinical impact. CC analysis showed 32% of patients with at least one aberration. FISH analysis detected chromosomal aberrations in 24% of patients and recovered 5 cases (13.5%) at normal karyotype (two 5q- syndromes, one del(7) case, two cases with PDGFR rearrangement). The aGCH detected 10 "new" unbalanced cases in respect of the CC, including one with alteration of the ETV6 gene. After mutational analysis, 33 patients (54%) presented at least one mutation and represented the only marker of clonality in 36% of all patients. The statistical analysis confirmed the prognostic role of CC either on overall or on progression-free-survival. In addition, deletions detected by aCGH and WT1 over-expression negatively conditioned survival. In conclusion, our work showed that 1) the addition of FISH (at least for chr. 5 and 7) can improve the definition of the risk score; 2) mutational analysis, especially for the TP53 and SF3B1, could better define the type of MDS and represent a "clinical warning"; 3) the aCGH use could be probably applied to selected cases (with suboptimal response or failure).

What Is the Clinical Utility of Repeat SNP Array Testing in the Follow-up of Myeloid Neoplasms?: A Retrospective Analysis of 44 Patients With Serial SNP Arrays

OBJECTIVES

Single-nucleotide polymorphism (SNP) arrays have been shown to identify cytogenetic abnormalities in myeloid neoplasms that may be missed by metaphase cytogenetics alone at initial diagnosis. This study examines the utility of serial SNP arrays in follow-up testing of myeloid neoplasms.

METHODS

We retrospectively reviewed results of SNP array testing in 44 patients with myeloid neoplasms and more than one SNP array study (n = 133 SNP arrays total; median, three per patient; range, two to eight per patient).

RESULTS

Baseline abnormalities were identified by SNP array in 35 (79%) of 44 (79%) compared with 18 (50%) of 36 by metaphase karyotype. In follow-up studies, clonal evolution was found by both SNP array and karyotyping in seven (15.9%), by metaphase karyotyping alone in six (13.6%), and SNP arrays alone in two (4.5%). Overall survival was not significantly different between patients with or without clonal evolution detected by SNP array.

CONCLUSIONS

This study, the first systematic examination of serial SNP arrays in myeloid neoplasms, confirms the clinical utility of SNP arrays at initial diagnosis but shows that clonal evolution of the karyotype can be detected by metaphase cytogenetics alone in most patients. Follow-up SNP array testing is not required in routine clinical use in most cases.

Cytogenetic profiling by FISH microscopy and comparison with light microscopy and complete blood count findings in myelodysplastic syndrome

Karyotype, bone marrow blast percentage and cytopenia influence the prognosis of myelodysplastic syndrome. We studied the abnormalities detected by fluorescence in situ hybridization (FISH) in myelodysplastic syndrome and associated haematological profile with abnormalities detected by FISH. Complete blood counts, peripheral blood and bone marrow of patients were evaluated for cytopenia, dysplasia and blasts. FISH probes were used to detect del(5q), gain of chromosome 8, de (7q/-7) and del(20 q). Multiple regression analysis was used to study the association of FISH abnormalities, age and sex with haematological profile. Mc Nemar's test studied the relationship between FISH abnormalities and dysplastic features in bone marrow. Cytogenetic abnormalities were detected by FISH in 25.7% of patients. Del(20 q) was seen in 14.2% of patients. FISH was able to predict changes in peripheral blood blast count by 80% (p ˂ 0.0001). Cytogenetic abnormalities were not seen in 74.2% of patients. Groups with FISH abnormalities have a different haematological profile, and these abnormalities have a significant effect on blast percentage.

Monitoring of the Clonal Fraction by Fluorescence In Situ Hybridization in Myelodysplastic Syndrome: Comparison With International Working Group Treatment Response Criteria

CONTEXT

-At the initial diagnosis of myelodysplastic syndrome (MDS) and/or during follow-up, the evaluation of chromosomal abnormalities is based on standard G-banding, whereas the utility of fluorescence in situ hybridization (FISH) is still debated.

OBJECTIVES

-To investigate whether interphase fluorescence in situ hybridization (iFISH) clone size at initial diagnosis of MDS is correlated with survival and whether changes in clonal fraction by iFISH are concordant with the MDS International Working Group response criteria during follow-up.

DESIGN

-A tailored FISH panel (-5/5q-, -7/7q-, +8, -20/20q-, and +1/1q+), based on reported cytogenetic changes in Korean patients with MDS, was performed in 81 patients with MDS at initial diagnosis and in 28 patients during follow-up.

RESULTS

-During follow-up, absolute increases in the clone size by iFISH by 20% or more, with relative increases of 50% or more, compared with previous specimens, were associated with transformation to acute myeloid leukemia (P = .001 and P = .002, respectively). Of the 28 patients with abnormal iFISH results, 7 (25%) showed discordance between iFISH and MDS International Working Group responses. Concordance between clone size by G-banding and iFISH was higher in the refractory cytopenia with unilineage dysplasia/refractory cytopenia with multilineage dysplasia group during follow-up, whereas the group with refractory anemia with excess blasts showed higher correlation at initial diagnosis.

CONCLUSIONS

-We conclude that iFISH can provide additional prognostic information and can predict the response to therapy in MDS.

Conventional karyotyping and fluorescence in situ hybridization: an effective utilization strategy in diagnostic adult acute myeloid leukemia

OBJECTIVES

Cytogenetics defines disease entities and predicts prognosis in acute myeloid leukemia (AML). Conventional karyotyping provides a comprehensive view of the genome, while fluorescence in situ hybridization (FISH) detects targeted abnormalities. The aim of this study was to compare the utility of karyotyping and FISH in adult AML.

METHODS

We studied 250 adult AML cases with concurrent karyotyping and FISH testing. Karyotyping was considered adequate when 20 or more metaphases were analyzed.

RESULTS

In total, 220 cases had adequate karyotyping and were classified as normal karyotype/normal FISH (n = 92), normal karyotype/abnormal FISH (n = 4), abnormal karyotype/normal FISH (n = 8), and abnormal karyotype/abnormal FISH (n = 116). The overall karyotype/FISH concordance rate was 97.7% with five discordant cases identified, four from the normal karyotype/abnormal FISH group and one from the abnormal karyotype/abnormal FISH group. No karyotype/FISH discordance was seen in the abnormal karyotype/normal FISH group for the FISH probes evaluated. FISH lent prognostic information in one (0.5%) of 220 cases with normal karyotype/abnormal FISH: CBFB-MYH11 fusion, indicating favorable prognosis.

CONCLUSIONS

In adult AML, FISH rarely provides additional information when karyotyping is adequate. We therefore propose an evidence-based, cost-effective algorithmic approach for routine conventional karyotype and FISH testing in adult AML workup.

Standardized fluorescence in situ hybridization testing based on an appropriate panel of probes more effectively identifies common cytogenetic abnormalities in myelodysplastic syndromes than conventional cytogenetic analysis: a multicenter prospective study of 2302 patients in China

In an attempt to establish the advantages of fluorescence in situ hybridization (FISH) studies over conventional cytogenetic (CC) analysis, a total of 2302 de novo MDS patients from 31 Chinese institutions were prospectively selected in the present study for both CC and standardized FISH analysis for +8, -7/7q-, -5/5q-, 20q- and-Y chromosomal abnormalities. CC analysis was successful in 94.0% of the patients; of these patients, 35.9% of the cases were abnormal. FISH analysis was successful in all 2302 patients and detected at least one type of common cytogenetic abnormality in 42.7% of the cases. The incidences of +8, -7/7q-, -5/5q-, 20q- and-Y chromosomal abnormalities by FISH were 4.1% to 8.7% higher than those by CC. FISH identified abnormalities in 23.6% of the patients exhibiting normal CC results and revealed that 20.7% of the patients with adequate normal metaphases (≥20) had abnormal clones. FISH identified cytogenetic abnormalities in 50.4% of the patients with failed CC analysis. In summary, our multicenter studies emphasised and confirmed the importance of applying standardized FISH testing based on an appropriate panel of probes to detect common cytogenetic abnormalities in Chinese de novo MDS patients, particularly those with normal or failed CC results.

Pathogenesis of myelodysplastic syndromes: an overview of molecular and non-molecular aspects of the disease

Myelodysplastic syndromes (MDS) are a group of clonal disorders arising from hematopoietic stem cells generally characterized by inefficient hematopoiesis, dysplasia in one or more myeloid cell lineages, and variable degrees of cytopenias. Most MDS patients are diagnosed in their late 60s to early 70s. The estimated incidence of MDS in the United States and in Europe are 4.3 and 1.8 per 100,000 individuals per year, respectively with lower rates reported in some Asian countries and less well estimated in other parts of the world. Evolution to acute myeloid leukemia can occur in 10-15% of MDS patients. Three drugs are currently approved for the treatment of patients with MDS: immunomodulatory agents (lenalidomide), and hypomethylating therapy [HMT (decitabine and 5-azacytidine)]. All patients will eventually lose their response to therapy, and the survival outcome of MDS patients is poor (median survival of 4.5 months) especially for patients who fail (refractory/relapsed) HMT. The only potential curative treatment for MDS is hematopoietic cell transplantation. Genomic/chromosomal instability and various mechanisms contribute to the pathogenesis and prognosis of the disease. High throughput genetic technologies like single nucleotide polymorphism array analysis and next generation sequencing technologies have uncovered novel genetic alterations and increased our knowledge of MDS pathogenesis. We will review various genetic and non-genetic causes that are involved in the pathogenesis of MDS.

The genetic basis and expanding role of molecular analysis in the diagnosis, prognosis, and therapeutic design for myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders of ineffective hematopoiesis that characteristically demonstrate peripheral blood cytopenia, bone marrow hypercellularity, and morphologically defined dysplasia of one or more hematopoietic lineages. Classical metaphase cytogenetics and judicious use of fluorescence in situ hybridization play central roles in the contemporary diagnosis and classification of MDS. An abundance of recent molecular studies are beginning to delineate additional genetic and epigenetic aberrations associated with these disorders. These alterations affect diagnosis, prognosis, and therapy, and with this understanding classification systems are evolving from a primarily hematological and morphological basis toward a multifactorial appreciation that includes histomorphology, metaphase cytogenetics, and directed molecular studies. In the present health-care environment, it is critical to develop a cost-effective, efficient testing strategy that maximizes the diagnostic potential of even limited specimens. Here, we briefly review the classical genetic approach to MDS, outline exciting new advances in the molecular understanding of this heterogeneous group of hematological neoplasms, and discuss how these advances are driving the evolution of classification and prognostic systems. Rapidly growing understanding of the genetic basis of MDS holds much promise for testing, and here we provide a frame of reference for discussion of current testing protocols and for addressing testing modalities likely to enter clinical practice in the near future.

The genetics of the myelodysplastic syndromes: Classical cytogenetics and recent molecular insights

Myelodysplastic syndromes (MDS) are a complex group of clonal hematopoietic disorders with an attendant diverse array of associated genetic changes. Conventional cytogenetics plays a prominent and well-established role in determining the contemporary diagnosis and prognosis of these disorders. More recently, molecular approaches have been useful in further characterizing this group of diseases, albeit in a largely experimental context, with the detection of changes at the single gene level including mutations, amplification and epigenetic phenomena. Nevertheless, we remain largely ignorant of the genetic underpinnings of MDS. Here we briefly review the established role of cytogenetics in MDS, and emphasize recent advances in unraveling the genetics of MDS, with a view towards how such findings might facilitate our ability to understand, diagnose and treat these disorders in a more rational manner.

Diagnosis and treatment of primary myelodysplastic syndromes in adults: recommendations from the European LeukemiaNet

Within the myelodysplastic syndrome (MDS) work package of the European LeukemiaNet, an Expert Panel was selected according to the framework elements of the National Institutes of Health Consensus Development Program. A systematic review of the literature was performed that included indexed original papers, indexed reviews and educational papers, and abstracts of conference proceedings. Guidelines were developed on the basis of a list of patient- and therapy-oriented questions, and recommendations were formulated and ranked according to the supporting level of evidence. MDSs should be classified according to the 2008 World Health Organization criteria. An accurate risk assessment requires the evaluation of not only disease-related factors but also of those related to extrahematologic comorbidity. The assessment of individual risk enables the identification of fit patients with a poor prognosis who are candidates for up-front intensive treatments, primarily allogeneic stem cell transplantation. A high proportion of MDS patients are not eligible for potentially curative treatment because of advanced age and/or clinically relevant comorbidities and poor performance status. In these patients, the therapeutic intervention is aimed at preventing cytopenia-related morbidity and preserving quality of life. A number of new agents are being developed for which the available evidence is not sufficient to recommend routine use. The inclusion of patients into prospective clinical trials is strongly recommended.

Application of FISH 7q in MDS patients without monosomy 7 or 7q deletion by conventional G-banding cytogenetics: does -7/7q- detection by FISH have prognostic value?

Chromosomal abnormalities are detected in 40-60% of patients with de novo myelodysplastic syndromes (MDS). This study used the FISH technique in 773 patients with de novo MDS without evidence of monosomy 7 (-7) or 7q deletion (7q-) by conventional G-banding cytogenetics (CC) to analyze their prognostic impact by FISH alone. FISH detected -7/7q- in 5.2% of patients. Presence of -7/7q- was associated with shorter overall survival than absence of such aberrations. Our results suggest that FISH 7q could be beneficial in patients with intermediate WHO morphologic risk stratification and no evidence of -7/7q- by CC.

The use of cytogenetic microarrays in myelodysplastic syndrome characterization

Various microarray platforms, including BAC, oligonucleotide, and SNP arrays, have been shown to -provide clinically useful diagnostic and prognostic information for patients with myelodysplastic syndromes (MDS). Clinically useful arrays are designed with specific purposes in mind and with attention to genomic content and probe density. All array types have been shown to detect genomic copy gains and losses, with SNP arrays having the added advantage of detecting copy neutral loss of heterozygosity (CNLOH). The finding of CNLOH has led to the identification of certain disease genes implicated in the initiation or progression of myeloid diseases. In addition, SNP karyotyping alone, or in conjunction with routine cytogenetics, can affect the outcome prediction and improve prognostic stratification of patients with MDS. Patients who were reclassified after array testing as having adverse-risk chromosomal findings correlated with poor survival. Results of over 25 published studies support the use of arrays in MDS testing. Because few balanced translocations are found in MDS, this disease is particularly amenable to microarray testing, and studies have shown better disease classification, identification of cryptic changes, and prognostication in this heterogeneous group of disorders. Novel genomic alterations identified by array testing may lead to better targeted therapies for treating patients with MDS.

Longitudinal bone marrow evaluations for myelodysplasia in patients with myeloma before and after treatment with lenalidomide

Lenalidomide (LEN) treatment in multiple myeloma (MM) results in a superior outcome. However, there is concern for increased myelodysplastic syndrome/acute myeloid leukemia (MDS/AML) associated with LEN. Thus, bone marrow morphology and cytogenetics studies from 40 patients were evaluated for early signs of MDS prior to therapy, during therapy and at follow-up. Newly diagnosed patients with MM treated with LEN and dexamethasone (LD) alone or followed by autologous stem cell transplant (LD/ASCT), or patients with relapsed/refractory MM treated with LEN, bendamustine and dexamethasone (BLD) were included. One patient developed MDS. Baseline prevalence of mild morphologic myelodysplasia was highest in pretreated patients with MM (BLD, 71%), but was also seen in newly diagnosed patients (LD and LD/ASCT, 17%). The prevalence of myelodysplasia did not increase over time. Thus, this study did not reveal rapidly emerging MDS in 39 of 40 patients with MM treated with LEN. The development of MDS in one patient suggests that longer follow-up is needed for all.

The utility of fluorescence in situ hybridization analysis in diagnosing myelodysplastic syndromes is limited to cases with karyotype failure

Fluorescence in situ hybridization (FISH) is being used increasingly in cytogenetic diagnosis of myelodysplastic syndromes (MDS). However, the utility of FISH in this role has not been well-defined. A total of 249 de novo MDS patients were submitted to karyotyping and FISH analysis for -5/del(5)(q31), -7/del(7)(q31), +8, -17/i(17)(q10), del(20)(q12), and -Y. Of the 234 patients with available karyotypic data, 143 cases (60.9%) demonstrated normal karyotype and 91 cases (39.1%) showed abnormal karyotype. FISH confirmed R-banding findings in 96.6% (226/234) of samples with successful karyotyping and detected cytogenetic abnormalities in 46.7% (7/15) of cases with karyotype failure. Of the 3.4% (8/234) patients showing discrepancies between FISH and R-banding, FISH revealed cytogenetic abnormalities in four patients with normal karyotypes and four patients with complex karyotypes. These results highlight FISH analysis has limited value in MDS cases with successful karyotyping and is only informative in MDS cases with karyotype failure.

Quantity of clonal cells detected by conventional cytogenetic analysis correlates with bone marrow blasts and survival in myelodysplastic syndromes

We performed quantitative and qualitative analyses of conventional cytogenetic analysis and interphase FISH results in 87 MDS patients. The quantity of clonal cells for each chromosome of CCA did not correlate with the result of iFISH (r, range 0.0761-1.0577). The clonal cell percentage in CCA was higher in patients with >5% bone marrow blasts than those with <5% (44.7% vs. 23.1%, p=0.017). Multivariate analysis showed that a high quantity of clonal cells in CCA analysis is an independent prognostic factor for overall survival in MDS (p=0.012).

Diagnostic yield of bone marrow and peripheral blood FISH panel testing in clinically suspected myelodysplastic syndromes and/or acute myeloid leukemia: a prospective analysis of 433 cases

It is unclear how often and in what setting fluorescence in situ hybridization (FISH) panels for myelodysplastic syndrome (MDS)/acute myeloid leukemia (AML) provide additional information over metaphase cytogenetics alone. Furthermore, the usefulness of peripheral blood vs bone marrow FISH has also not been directly compared. We prospectively compared metaphase cytogenetics and FISH for -5/5q-, -7/7q-, +8, and 20q- in 433 cases of suspected MDS/AML. FISH testing was abnormal in 6 (14%) of 43 and 10 (19%) of 54 cases with fewer than 20 normal metaphases or no growth, respectively. FISH was only rarely abnormal in cases with 20 normal metaphases obtained (6/222 [2.7%]). Comparison of peripheral blood and bone marrow results in 48 cases showed abnormal peripheral blood FISH results in 18 (69%) of 26 cases with abnormal bone marrow FISH results and in 5 (23%) of 22 cases with normal bone marrow FISH results. These findings, the largest published comparison of FISH vs metaphase cytogenetics in MDS/AML, provide a rational strategy for FISH testing in peripheral blood and bone marrow.

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.

Prognostic molecular markers in myelodysplastic syndromes

Cytogenetic findings in myelodysplastic syndromes play an important role in diagnosis, prognostication and clinical decision making. Therefore, they became an important aspect in scoring systems such as the International Prognostic Scoring System (IPSS) and the WHO-adapted Prognostic Scoring System (WPSS). Ongoing efforts to refine the categorization of karyotypes with regard to prognosis and therapeutic options will change scoring systems in the near future. In order to learn more about the pathophysiology of myelodysplastic syndromes, various molecular genetic aberrations are identified and their impact on prognosis discussed. New screening methods such as gene expression or single nucleotide polymorphism analysis are good candidates to find entrance in clinical practice in the future as they are useful tools in further elucidation of the underlying defects in myelodysplastic syndromes and the development of more specific classifications of the disease concerning risk assessment.

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.

Fluorescence in situ hybridization testing for -5/5q, -7/7q, +8, and del(20q) in primary myelodysplastic syndrome correlates with conventional cytogenetics in the setting of an adequate study

Multiple studies, with differing results, have compared the added sensitivity of fluorescence in situ hybridization (FISH) with conventional cytogenetics (CC) to detect genetic abnormalities in myelodysplastic syndrome (MDS). We hypothesized that in the setting of an adequate CC study, FISH would correlate with microscopic genetic abnormalities involving chromosomes 5, 7, 8, and 20. We performed FISH for -5/5q, -7/7q, +8, and del(20q) on 102 MDS cases with normal CC (> or =20 consecutive metaphases) and on 35 MDS cases with abnormal CC. Of the 102 MDS cases with normal CC, only 1 was discrepant between FISH (showing +8) and CC (<1% of total cases). Of the 35 MDS cases with abnormal CC, 1 showed a minor discrepancy (-5 by CC vs del(5q) by FISH). FISH for MDS abnormalities (-5/5q, -7/7q, +8, and del(20q)) correlates with an adequate karyotypic result without increased sensitivity. Consequently, we recommend that FISH not be performed in MDS cases with an adequate karyotype.

Myelodysplastic syndrome in elderly patients: correlation of CBC with cytogenetic and FISH analysis

Unexplained anemia in the elderly could represent myelodysplastic syndrome (MDS). We assessed the utility of using a fluorescence in situ hybridization (FISH) panel for common chromosomal abnormalities seen in MDS. A total of 101 elderly outpatients with anemia of unknown etiology were evaluated. Complete blood count, bone marrow biopsy, conventional cytogenetic analysis (CC), and FISH panel were reviewed. A total of 21 (21%) of the 101 patients had MDS. A combination of CC and FISH identified chromosomal abnormalities in 17 (81%) of the patients with MDS. The remaining 4 (19%) were diagnosed with MDS based solely on morphologic criteria. Except in two cases, FISH did not reveal abnormalities not already detected by CC. Furthermore, MDS patients infrequently had isolated anemia (14%) as opposed to those without MDS (75%). A MDS FISH panel is not more sensitive than CC in elderly outpatients with unexplained anemia. MDS is more likely if in addition to anemia, leukopenia and/or thrombocytopenia are also present.

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.

Phosphoinositide-Phospholipase C β1 Mono-Allelic Deletion Is Associated With Myelodysplastic Syndromes Evolution Into Acute Myeloid Leukemia

Purpose

To evaluate the association between the presence of phosphoinositide-phospholipase C β1 (PI-PLCβ1) mono-allelic deletion with the clinical outcome of myelodysplastic syndromes (MDS) patients.

Methods

PI-PLCβ1, PI-PLCβ4, and PI-PLCγ1 cytogenetic investigations were performed on 80 newly diagnosed MDS patients (18 low risk, 26 intermediate 1, 18 intermediate 2, 18 high risk) comparing the results with the clinical outcome of the patients. Moreover, fluorescent in situ hybridization results were validated by real-time polymerase chain reaction (PCR). Finally, PI-PLCβ1 gene and protein expression were assessed by both real-time PCR and immunocytochemical experiments.

Results

Collectively, 35 (43.75%) of 80 of the MDS patients showed a specific mono-allelic deletion of PI-PLCβ1. Kaplan-Meier analysis revealed a significant association (P < .0001) between the PI-PLCβ1 mono-allelic deletion and a higher risk of evolution into acute myeloid leukemia (AML), since 23 of 35 MDS patients (65.7%) bearing the PI-PLCβ1 mono-allelic deletion evolved into AML. Even in multivariate analysis, the PI-PLCβ1 mono-allelic deletion retained a higher significance, with a P < .001, as a prognostic factor of evolution into AML (odds ratio [OR] 1.83; 95% CI, 2.26 to 17.24; P = .00045). Finally, PI-PLCβ1 deletion was related to an altered gene and protein expression.

Conclusion

PI-PLCβ1 mono-allelic deletion is associated with a worse clinical outcome in MDS patients, hinting at the identification of a new group at higher risk of AML evolution and representing a reliable prognostic tool. Moreover, targeting PI-PLCβ1 pathways might emerge as a new therapeutic strategy for MDS.

Myelodysplastic syndromes with del(5q): indications and strategies for cytogenetic testing

Cytogenetics is a major predictor of disease behavior and treatment outcome in myelodysplastic syndromes (MDS). Deletion of the long arm of chromosome 5, del(5q), is the most common chromosomal abnormality found in patients with MDS. The development of lenalidomide (Revlimid; Celgene, Summit, NJ) as an effective targeted therapy for low/intermediate-risk MDS with a del(5q) has increased the importance of karyotyping in disease management. In the present review, the importance of an accurate cytogenetic diagnosis in del(5q) MDS, its impact on prognosis, and the effect it can have on the choice of treatment was discussed. In addition, the strengths and limitations of conventional and novel cytogenetic testing techniques currently available for patients with del(5q) MDS were evaluated. A practical diagnostic algorithm was provided to help facilitate the early detection and optimal treatment of MDS patients with a del(5q) abnormality. While the gold standard for genetic testing remains metaphase karyotyping, emerging novel molecular techniques such as fluorescence in situ hybridization may provide clinically valuable complementary and supplemental data.

FISH in der Diagnostik hämatologischer Neoplasien

Sämtliche hämatologische Neoplasien zeigen eine große klinische Variabilität. Allerdings lassen sich die Entitäten in eine Vielzahl von Prognose bestimmenden Subtypen auf der Basis genetischer Marker einteilen. Die individuelle Abstimmung der Therapie erfordert daher eine exakte Klassifikation des genetischen Subtyps. In Verbindung mit der Chromosomenanalyse spielt die Fluoreszenz-in-situ-Hybridisierung (FISH) dabei eine zentrale Rolle – für die weitere Aufklärung von Befunden der Chromosomenanalyse, z. B. bei akuten Leukämien, oder die Klassifikation diverser Subtypen, wie bei den Non-Hodgkin-Lymphomen. In Abhängigkeit von der Erkrankung kommt der FlSH-Analyse eine unterschiedliche Bedeutung zu. Sie wird zum einen als Methode der ersten Wahl zur genetischen Charakterisierung einer Erkrankung, z. B. des multiplen Myeloms, angewandt, oder kommt in Kombination mit der Chromosomenbänderungsanalyse zum Einsatz. Ferner kommt ihr eine essenzielle Bedeutung zu, wenn eine rasche Bestätigung einer Diagnose erforderlich ist, wie bei der akuten Promyelozytenleukämie mit t(15;17)/PML-RARA-Rearrangement, bei der ein sofortiger Therapiebeginn mit All-trans-Retinsäure (ATRA) notwendig ist.

New recurrent deletions in the PPARgamma and TP53 genes are associated with childhood myelodysplastic syndrome

Myelodysplastic syndrome (MDS) is a rare hematological malignancy in children. It was performed FISH analysis in 19 pediatric MDS patients to investigate deletions involving the PPARgamma and TP53 genes. Significant losses in the PPARgamma gene and deletions in the tumor suppressor gene TP53 were observed in 17 and 18 cases, respectively. Using quantitative RT-PCR, it was detected PPARgamma transcript downexpression in a subset of these cases. G-banding analysis revealed 17p deletions in a small number of these cases. One MDS therapy-related patient had neither a loss of PPARgamma nor TP53. These data suggest that the PPARgamma and TP53 genes may be candidates for molecular markers in pediatric MDS, and that these potentially recurrent deletions could contribute to the identification of therapeutic approaches in primary pediatric MDS.

Idiopathic cytopenia of undetermined significance (ICUS) versus low risk MDS: The diagnostic interface

It may sometimes be difficult to diagnose low risk MDS in patients with mild cytopenia. We report on 10 patients with mild to marked, unexplained cytopenia without definitive signs of a myeloid neoplasm. In two patients, a karyotype-abnormality (trisomy 14; monosomy 7) was detected in a small subset of bone marrow cells. Progression to overt MDS was seen in two patients including the one with monosomy 7. In the remaining cases, no MDS developed in a follow-up of at least 6 months. The phrase "idiopathic cytopenia of undetermined significance (ICUS)", as also suggested by Mufti and co-workers, is proposed and long term follow-up is recommended to assess the evolution.

Definitions and standards in the diagnosis and treatment of the myelodysplastic syndromes: Consensus statements and report from a working conference

The classification, scoring systems, and response criteria for myelodysplastic syndromes (MDS) have recently been updated and have become widely accepted. In addition, several new effective targeted drugs for patients with MDS have been developed. The current article provides a summary of updated and newly proposed markers, criteria, and standards in MDS, with special reference to the diagnostic interface and refinements in evaluations and scoring. Concerning the diagnostic interface, minimal diagnostic criteria for MDS are proposed, and for patients with unexplained cytopenia who do not fulfill these criteria, the term 'idiopathic cytopenia of uncertain significance' (ICUS) is suggested. In addition, new diagnostic and prognostic parameters, histopathologic and immunologic determinants, proposed refinements in scoring systems, and new therapeutic approaches are discussed. Respective algorithms and recommendations should facilitate diagnostic and prognostic evaluations in MDS, selection of patients for therapies, and the conduct of clinical trials.

Evaluation of recurring cytogenetic abnormalities in the treatment of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are clinically heterogeneous, but the presence of specific cytogenetic abnormalities can predict disease manifestations, provide a basis for prognosis, and direct treatment. Conventional cytogenetic analysis is instrumental in identifying chromosomal abnormalities in MDS and novel genetic methods may provide supplementary information. Treatment with lenalidomide was recently shown to be effective in MDS, particularly in those cases with del(5q), resulting in durable cytogenetic remission and hematological responses. In this paradigm, diagnosis of the del(5q) abnormality would be essential to predicting response to therapy.

The myelodysplastic syndromes: diagnosis and treatment

The myelodysplastic syndromes (MDSs) are common, acquired, clinically challenging hematologic conditions that are characterized by bone marrow failure and a risk of progression to acute leukemia. These disorders can arise de novo, especially in elderly patients or, less often, as a consequence of prior chemotherapy or radiotherapy for an unrelated disease. The MDS classification systems were revised recently and updated. These refined classification and prognostic schemes help stratify patients by their risk of leukemia progression and death; this knowledge can help clinicians select appropriate therapy. Although many treatments for MDS have been proposed and evaluated, at present, only hematopoietic stem cell transplantation offers any real hope for cure, and no available therapy beyond general supportive care offers benefit to more than a minority of patients. However, recent clinical trials enrolling patients with MDS have reported encouraging results with use of newer drugs, including lenalidomide, decitabine, and darbepoetin alfa. Other exciting treatment regimens are being tested. Here, we present a contemporary, practical clinical approach to the diagnosis and risk-stratified treatment of MDS. We review when to suspect MDS, detail how to evaluate patients who may have a form of the condition, explain key features of treatments that are currently available in the United States, and summarize a general, common-sense therapeutic approach to patients with MDS.

ABL1 amplification in T-cell acute lymphoblastic leukemia

ABL1 amplification, due to a cryptic episomal translocation NUP214/ABL1, is a novel finding in T-cell acute lymphoblastic leukemia (ALL). Here we report on the incidence and clinical features of this genetic defect in a series of 30 consecutive adult T-cell ALL patients. Multiple copies of the ABL1 gene were detected in two patients (6.6%), one with the karyotype 46,XY,t(1;3)(p36;p21),del(6)(q23)/46,XY and the other without analyzable metaphases. Metaphase/interphase fluorescence in situ hybridization (FISH) detected multiple uncountable signals corresponding to ABL1 in mitotic cells and nuclei from both patients. In one patient, no signals corresponded with the 9p21 chromosomal region, which contains the p16INK4a gene, and in the other one signal was observed. Quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) demonstrated that in these patients ABL1 gene expression was 14- and 18-fold greater than in normal controls, and returned to normal levels only when complete remission was achieved. We reached the following conclusions: (1) FISH is the only technique that promptly identifies T-cell ALL patients with ABL1 amplification, (2) quick identification with FISH is fundamental in the clinic because this T-cell ALL subset is imatinib sensitive but may become resistant due to development of additional mutations, and (3) ABL1 quantitative RT-PCR may be easily applied to monitor minimal residual disease.

Genetic testing in the myelodysplastic syndromes: molecular insights into hematologic diversity

The myelodysplastic syndromes (MDS) are associated with a diverse set of acquired somatic genetic abnormalities. Bone marrow karyotyping provides important diagnostic and prognostic information and should be attempted in all patients who are suspected of having MDS. Fluorescent in situ hybridization (FISH) studies on blood or marrow may also be valuable in selected cases, such as patients who may have 5q- syndrome or those who have undergone hematopoletic stem cell transplantation. The MDS-associated cytogenetic abnormalities that have been defined by karyotyping and FISH studies have already contributed substantially to our current understanding of the biology of malignant myeloid disorders, but the pathobiological meaning of common, recurrent chromosomal lesions such as del(5q), del(20q), and monosomy 7 is still unknown. The great diversity of the cytogenetic findings described in MDS highlights the molecular heterogeneity of this cluster of diseases. We review the common and pathophysiologically interesting genetic abnormalities associated with MDS, focusing on the clinical utility of conventional cytogenetic assays and selected FISH studies. In addition, we discuss a series of well-defined MDS-associated point mutations and outline the potential for further insights from newer techniques such as global gene expression profiling and array-based comparative genomic hybridization.