Increasing incidence of myelodysplastic syndromes: real or fictitious?

MDS patient registries - achievements and challenges

Since the late 1980s, patient registries have played a pivotal role in the elucidation of rare diseases. For myelodysplastic syndromes (MDS), they revealed the disease actually to be diverse rather than rare. Registry data enabled the definition of various MDS subtypes and prognostic scores tailoring therapy. These classifications have been revised and refined several times, and the differential diagnosis of MDS has become increasingly complex. At the same time, the diagnosis has been made more commonly and no longer by specialized centers of expertise only. Consequently, several registries have collected data with different focuses and from different patient subpopulations. The current review presents three MDS registries and their rationale, scope, design, and achievements. All three complement each other and will remain a mainstay to advance the knowledge on MDS as well as to validate the outcomes of clinical trials. However, delineation of subtypes after the most recent WHO and IPC revisions, as well as the determination of the newest risk score M of the International Prognostic Scoring System (IPSS-M), no longer just shift cut-offs but are based on multivariate compilations of highly specific genetic information. This paradigm shift involves challenging registries with respect to the assignment of all patients for whom this information has not yet been available.

Is bone marrow examination always necessary to establish the diagnosis of myelodysplastic syndromes? A proposed non-invasive diagnostic model

A non-invasive myelodysplastic syndromes (MDS) diagnostic model would allow for care while avoiding invasive bone marrow examinations (BME). BME-established MDS patients were compared to non-MDS (BME-excluded) patients. Variables (gender, age, hemoglobin (Hb), mean red blood cell corpuscular volume (MCV), platelet (PLT), and white blood cell (WBC)) were combined with multivariate logistic regression; a probability score (Y) was calculated. MDS (n = 48) and non-MDS (n = 63) patients were used to establish the model. The ROC was drawn, giving an AUC of 0.748 (95% CI: 0.656-0.84). Two cutoff values were used for Y. Y ≥ 0.633: high likelihood (positive predictive value (PPV) = 85%); Y ≤ 0.288: low likelihood (negative predictive value (NPV) = 81%) of MDS. The first group is defined as probable MDS (pMDS); the second, probably not MDS (pnMDS). The model was validated with 40 additional patients (20 with and 20 without MDS). Using clinical and lab data, we could diagnose or exclude MDS in about half of the patients, avoiding BME. Future work will use larger cohorts of patients to improve and further validate the model.

Trends of classification, incidence, mortality, and survival of MDS patients in Switzerland between 2001 and 2012

Myelodysplastic syndromes (MDS) are emerging disorders of the elderly with an increasing burden on healthcare systems. He we report on the first population-based, epidemiological analysis of patients diagnosed with MDS in Switzerland between 2001 and 2012. The aim of this study was to characterize the extent and limitations of currently available population-based, epidemiological data and formulate recommendations for future health services research. The investigated outcomes comprised trends of annual case frequency, classification of morphological subtypes, incidence, mortality and survival. Annual case frequency increased by 20% (from 263 to 315 cases per year), whereas age-standardized incidence-/mortality-rates remained stable (2.5/1.1 per 100'000 person-years). This observation reflects population growth as well as higher diagnostic awareness and not an increase of age-specific risk. However, it will inevitably influence the future prevalence of MDS and the impact on healthcare systems. Reporting of classification in MDS subtypes was poor with modest improvement from 20% to 39% and increased awareness for mainly higher-risk diseases. Relative survival for all patients at 5-years (RS) ranged between 37 and 40%. Significant better RS was found for younger compared to older higher-risk MDS patients (48% vs. 17%), reflecting the effect of allogeneic hematopoietic stem-cell transplantation. However, no survival advantage was found in elderly patients after introduction of hypomethylating agents as standard for care in this patient group. Our data is in line with results from other MDS and cancer registries. It allows formulating recommendations for future collaborative health services research on MDS patients with national and international partners.

Loss of SHIP-1 protein expression in high-risk myelodysplastic syndromes is associated with miR-210 and miR-155

The myelodysplastic syndromes (MDSs) comprise a group of disorders characterized by multistage progression from cytopenias to acute myeloid leukemia (AML). They display exaggerated apoptosis in early stages, but lose this behavior during evolution to AML. The molecular basis for loss of apoptosis is unknown. To investigate this critical event, we analyzed phosphatidylinositol (PI) 3'kinase signaling, implicated as a critical pathway of cell survival control in epithelial and hematological malignancies. PI 3'kinase activates Akt through its production of 3' phosphoinositides. In turn, the phosphoinositides are dephosphorylated by two lipid phosphatases, PTEN and SHIP-1, in myeloid cells. We studied primary MDS-enriched bone marrow cells and bone marrow sections by western blotting, immunohistochemistry, immunocytochemistry and quantitative PCR for components of the SHIP/PTEN/PI 3'kinase signaling circuit. We reported constitutively activated Akt, variable levels of PTEN and uniformly decreased SHIP-1 expression in MDS progenitor cells. Overexpression of SHIP-1, but not the phosphatase-deficient form, inhibited myeloid leukemic growth. Levels of microRNA (miR)-210 and miR-155 transcripts, which target SHIP-1, were increased in CD34(+) MDS cells compared with their normal counterparts. Direct binding of miR-210 to the 3' untranslated region of SHIP-1 was confirmed by luciferase reporter assay. Transfection of a myeloid cell line with miR-210 resulted in loss of SHIP-1 protein expression. These data suggest that miR-155 and miR-210/SHIP-1/Akt pathways could serve as clinical biomarkers for disease progression, and that miR-155 and miR-210 might serve as novel therapeutic targets in MDS.

Azacytidine (Vidaza(R)) in the treatment of myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are a heterogeneous group of disorders that manifest as bone marrow failure with the risk of life threatening infections and bleeding. A third of these patients may transform to acute leukemia. Age and co-morbidities have limited treatment in the majority to supportive care with a minority of patients eligible for the only curative modality to date, allogeneic stem cell transplantation. The advent of targeted therapy has increased the repertoire of therapeutic options. In particular the methyl transferase inhibitor 5 Azacytidine, that targets epigenetic changes in MDS, has been shown to be effective in up to 60% of patients in a Phase III randomized controlled trial comparing it with best supportive care and has been licensed by the US Food and Drug Administration for use in all subtypes of MDS. It has been shown to prolong time to leukemic transformation (21 vs 12 months with 3% transforming to leukemia p=0.0001) and is the only disease-modifying drug. Patients with monosomy 7, trisomy 8, and diploid chromosomes appear to particularly benefit with the former deriving sustained remissions. As an outpatient therapy, with an acceptable side effect profile, treatment with Azacytidine needs to be considered in all MDS patients who are eligible for treatment.

Myelodysplastic syndrome and histone deacetylase inhibitors: "to be or not to be acetylated"?

Myelodysplastic syndrome (MDS) represents a heterogeneous group of diseases with clonal proliferation, bone marrow failure and increasing risk of transformation into an acute myeloid leukaemia. Structured guidelines are developed for selective therapy based on prognostic subgroups, age, and performance status. Although many driving forces of disease phenotype and biology are described, the complete and possibly interacting pathogenetic pathways still remain unclear. Epigenetic investigations of cancer and haematologic diseases like MDS give new insights into the pathogenesis of this complex disease. Modifications of DNA or histones via methylation or acetylation lead to gene silencing and altered physiology relevant for MDS. First clinical trials give evidence that patients with MDS could benefit from epigenetic treatment with, for example, DNA methyl transferase inhibitors (DNMTi) or histone deacetylase inhibitors (HDACi). Nevertheless, many issues of HDACi remain incompletely understood and pose clinical and translational challenges. In this paper, major aspects of MDS, MDS-associated epigenetics and the potential use of HDACi are discussed.

Review of stem-cell transplantation for myelodysplastic syndromes in older patients in the context of the Decision Memo for Allogeneic Hematopoietic Stem Cell Transplantation for Myelodysplastic Syndrome emanating from the Centers for Medicare and Medicaid Services

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal hematopoietic stem-cell disorders that result in varying degrees of cytopenia and risk of transformation into acute leukemia. Allogeneic stem-cell transplantation (SCT) is the only known cure for this disease. The treatment is routinely used for younger patients, but only a minority of patients older than the age of 60 undergo this procedure. The overall MDS incidence is 3.3 per 100,000, but the incidence in patients older than age 70 is between 15 and 50 per 100,000. The median age at presentation is 76 years. Medicare-age patients 65 or older represent 80% of the total population receiving an MDS diagnosis. In the United States, one of the obstacles to SCT for older patients with MDS has been lack of third party reimbursement. On August 4, 2010, the Centers for Medicare and Medicaid Services released their Decision Memo for Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) for Myelodysplastic Syndrome. This memo states: "Allogeneic HSCT for MDS is covered by Medicare only for beneficiaries with MDS participating in an approved clinical study that meets the criteria below…. " In this review, we will summarize what is known regarding the role of allogeneic SCT in older patients as well as other elements that should be included within clinical trials that can provide the evidence necessary to demonstrate that allogeneic SCT should be a covered benefit for Medicare beneficiaries.

[Myelodysplastic syndrome with erythroblastopenia]

Myelodysplastic syndrome with erythroid hypoplasia or erythroblastopenia has not yet been clearly defined, and in most patients it is mistaken for acquired pure red cell aplasia. Including one additional patient reported in this article, a literature review revealed only 50 cases over the last 20 years. These patients were predominantly elderly males, all required regular packed red cell transfusions, and they had a poor prognosis, mainly because of acute transformation. The mechanisms of erythroid aplasia remain unclear. However, recent data suggest the association of an intrinsic stem cell defect with immunological implication.

A distinct expression of various gene subsets in CD34+ cells from patients with early and advanced myelodysplastic syndrome

Gene expression profiles of CD34+ cells were compared between 51 MDS patients and 7 controls. The most up-regulated genes in patients included HBG2, HBG1, CYBRD1, HSPA1B, ANGPT, and MYC, while 13 genes related to B-lymphopoiesis showed down-regulation. We observed in advanced MDS patients decreased expression of genes involved in cell cycle control, DNA repair and increased expression of proto-oncogenes, angiogenic and anti-apoptic genes. The results suggest that increased cell proliferation and resistance to apoptosis together with a loss of cell cycle control, damaged DNA repair and altered immune response may play an important role in malignant clone expansion in MDS.

Abnormal Expression of C3ORF9 Gene in Patients with Myelodysplastic Syndromes

Myelodysplastic Syndrome (MDS) cells present genetic instability and dysregulation of the gene C30RF9, which was isolated from an MDS cDNA library and codes for a putative protein. We studied the expression of C30RF9 in MDS syndromes to contribute to the understanding of the pathophysiology of MDS. One hundred and thirty-one patients and 35 healthy controls were involved in our study. Bone marrow aspirates and isolated CD34+ cells were used. Gene expression was estimated by quantitative PCR. C3ORF9 was found to be down-regulated in patients with CMML compared to the controls (p<0.01). There was no difference between RARS and the controls (p=0.1), while increased expression was found in RA, RAEB and RAEB-T (p< 0.01 for all). No mutations or polymorphism were detected in our population. CD34+ cells expressed higher levels of C30RF9 (p<0.01) in patients. The gene expression was correlated to the percentage of + cells in RAEB and RAEB-T (r= 0.64). The altered C30RF9 expression was possibly due to different gene regulation in these patients and/or to the increased CD34+ cells.

Clinical study on the serum carcinoembryonic antigen, CA 19-9, CA 50 and α-fetoprotein levels in patients with myelodysplastic syndromes

The present study aimed to determine the serum carcinoembryonic antigen (CEA), CA 19-9, CA 50 and alpha-fetoprotein (alpha-FP) levels between patients with myelodysplastic syndromes (MDS) at diagnosis and controls to clarify their potential clinical significance. A case-control investigation was conducted over a three year period, covering 95 MDS cases and 95 age- and gender-matched controls. Mean serum CEA levels were significantly higher (P = 0.0002) in MDS patients at diagnosis than in hospital controls. Adjusting for age, gender, tobacco consumption, serum CA 19-9, CA 50 and alpha-FP levels, there is statistically significant evidence that serum CEA values are associated with increased risk of MDS (odds ratio = 2.33, 95% confidence interval = 1.56 - 3.49). Six patients with MDS developed malignancies 4-9 months after the diagnosis of myelodysplasia. Serum CEA could be used as marker together with other important diagnostic tools for evaluating an underlying or developing malignancy in patients suffering from MDS.

NUP98-HOX translocations lead to myelodysplastic syndrome in mice and men

The myelodysplastic syndromes (MDS) are a group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, peripheral blood cytopenias, dysplasia, and a propensity for transformation to acute myeloid leukemia (AML). A wide spectrum of genetic aberrations has been associated with MDS, including chromosomal translocations involving the NUP98 gene, most commonly leading to fusions of NUP98 with abd-b group HOX genes, including HOXD13. We used vav regulatory elements to direct expression of a NUP98-HOXD13 (NHD13) fusion gene in hematopoietic tissues. NHD13 transgenic mice faithfully recapitulate all the key features of MDS, including peripheral blood cytopenias, bone marrow dysplasia and apoptosis, and transformation to acute leukemia. The MDS that develops in NHD13 transgenic mice is highly lethal; within 14 months, 90% of the mice died of either leukemic transformation or severe anemia and leukopenia due to progressive MDS. These mice provide a preclinical model that can be used for the evaluation of MDS therapy and biology.

Evolving new treatment for myelodysplastic syndromes

Over the last several years, there has been substantial progress in the definition, diagnosis, and management of myelodysplastic syndromes (MDSs). This progress includes the new World Health Organization classification and the revised standardized response criteria to be applicable to most new compounds, which, taken together with the International Prognostic Scoring System, provide a uniform basis for the management of individual patients. The recent introduction of certain new agents, as well as an apparent increase in the use of stem cell transplantation with a variety of so-called reduced-intensity settings, has indeed raised the hope that we are entering a new era of MDS treatment.

The incidence and impact of thrombocytopenia in myelodysplastic syndromes

Thrombocytopenia and platelet dysfunction contribute to hemorrhagic complications in the myelodysplastic syndromes (MDS). Reliable data regarding the frequency and consequences of thrombocytopenia in MDS are lacking. An extensive literature review indicated that the prevalence of thrombocytopenia (platelets<100x10(9)/L) in MDS ranged from 40% to 65%; the median frequency of thrombocytopenia prior to any MDS therapy was 65% (range, 23-93%). A retrospective review of patients who were referred to the University of Texas M. D. Anderson Cancer Center (MDACC) identified 1605 of 2410 patients (67%) with thrombocytopenia at referral. Of these, 1756 patients were classified using the International Prognostic Scoring System (IPSS), and 896 patients (51%) had intermediate-2 or high-risk disease. Treatment-related thrombocytopenia was observed in studies that involved azacitidine, tipifarnib, decitabine, lenalidomide, sirolimus, and combination chemotherapy with idarubicin, cytarabine, and topotecan. The reported incidence of hemorrhagic complications in the literature ranged from 3% to 53%, and the frequency of hemorrhagic deaths ranged from 14% to 24%. At MDACC, 460 patients had a coded cause of death: hemorrhage as a contributory cause of death, 20%; hemorrhage as the only cause of death, 10%. Thrombocytopenia was common in MDS, and there was an increased prevalence in higher risk IPSS categories. Many approved and investigational MDS therapies caused or exacerbated preexisting thrombocytopenia. The incidence of severe bleeding in MDS was greater than reported in current guidelines.

Evolving trends in the treatment of low-risk myelodysplastic syndromes: immunomodulation and beyond?9th European Hematology Association Congress Geneva, Switzerland, 10?13 June 2004

The 9th European Hematology Association Congress, held in Geneva, Switzerland, from 10 through 13 June 2004, offered a number of educational programmes that focused on myelodysplastic syndromes (MDS). This report will summarize the material presented at the educational symposium entitled 'Evolving Trends in the Treatment of Low-Risk MDS: Immunomodulation and Beyond'. The overview of the presentations includes a comparative review of the classification systems for MDS; a discussion of treatment strategies and management issues for patients in lower risk disease categories; a description of a novel class of immunomodulators, the IMiDs((R)), and a presentation of updated data from clinical trials of the IMiD compound, lenalidomide, in the treatment of MDS.

Strategies for achieving transfusion independence in myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a group of complex diseases of the myeloid stem cell that result in chronic cytopenias. In some instances, these disorders may progress to acute myeloid leukemia. Patients with MDS frequently experience chronic, symptomatic anemia, and many become dependent on chronic transfusions of packed red blood cells. However, long-term transfusion dependence has clinical and economic consequences, including a potentially negative impact on patients' quality of life (QOL). Recently, studies have investigated various strategies to reduce or eliminate transfusion needs in MDS patients. Supportive measures with hematopoietic growth factors such as erythropoietin are often less effective in MDS-associated anemia than in anemia from other causes, but some patients may benefit from this approach. Treatment with other agents, such as antithymocyte globulin, azacitidine, decitabine, thalidomide, and lenalidomide, has resulted in transfusion independence in some subsets of MDS patients. Nurses who care for patients with MDS should be aware of the impact of transfusion dependence on the patient's QOL, as well as the benefits and risks of the various other treatment options available to these patients. Such knowledge will enable the nurse to provide accurate, relevant information, so that patients can make informed choices regarding treatment options for MDS.

Secondary myelodysplastic syndrome after hydroxychloroquine therapy

Primary myelodysplastic syndromes (MDS) occur in the absence of exposure to ionizing radiation, chemotherapeutic agents or myelotoxic drugs, whereas secondary MDS occurs in the presence of such exposure. We encountered 4 patients among 217 patients on hydroxychloroquine for rheumatological conditions in 2005 diagnosed with MDS. Two patients were male and two were female; the median age was 69.75 years, (range 65-76). The dose of hydroxychloroquine for all patients was 400 mg daily with median treatment duration of 10.5 years and a range of 6-16. All patients had bone marrow biopsy confirmation of the diagnosis of MDS. The incidence of MDS in a group older than 70 years ranges from 15 to 50/100,000 persons per year. The diagnosis of 4 cases of MDS among 217 patients in 1 year is approximately 123-137-fold higher than the risk of MDS in the general population aged more than 70 years (P < 0.001) and suggests that long-term treatment with hydroxychloroquine is associated with an increased risk of developing secondary MDS.

The spectrum of myelodysplastic syndromes post-solid organ transplantation: A single institutional experience

An increased incidence of acute myeloid leukemia (AML) has recently been documented in patients post-solid organ transplantation but the incidence and types of myelodysplastic syndromes (MDS) occurring in this patient population are not known. We identified 5 patients (3M, 2F, age 48-64 years) who developed MDS ranging from 1.8 to 25 years (median 4.2 years) post-solid organ transplantation, only 2 patients had received azathioprine. The cumulative incidence of MDS in heart and lung transplant recipients at 15 years was 0.5% and 1.8%, respectively, which is markedly higher compared to the general population. Low-risk types of MDS predominated, 3 of 5 patients are alive (median 3.9 years) since diagnosis. Deletions of chromosome 20q, which have not been previously reported in post-transplant MDS/AML, were identified in 3 cases. Our findings expand the morphologic and cytogenetic spectrum of MDS occurring post-solid organ transplantation and suggest that mechanisms beside azathioprine toxicity might be important in disease pathogenesis.

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.

Advances in the management of low- to intermediate-risk myelodysplastic syndrome: Integrating the National Comprehensive Cancer Network guidelines

Myelodysplastic syndromes (MDSs) are a group of hematologic diseases that present unique challenges for oncology nurses, especially because patients with the disorders are being seen more often in oncology practices. An increasing array of therapeutic options are available, and the National Comprehensive Cancer Network published its first clinical practice guidelines for MDSs in 2004. This article provides oncology nurses with the most recent data on supportive care as well as emerging therapies for patients with low- to intermediate-risk MDS.

Impact of growth factors in the regulation of apoptosis in low-risk myelodysplastic syndromes

Increased apoptosis of hematopoietic progenitors is a hallmark of myelodysplastic syndromes (MDS) and results in ineffective hematopoiesis. Erythroid apoptosis is thought to be the main mechanism underlying the severe anemia observed in the low-risk subgroups, refractory anemia (RA) and RA with ringed sideroblasts (RARS). Treatment with erythropoietin (Epo) alone or in combination with granulocyte colony-stimulating factor (G-CSF) may significantly improve anemia and reduce bone marrow apoptosis. A synergistic effect between Epo and G-CSF has been observed in the clinic, in particular in RARS. However, the molecular mechanisms beyond the anti-apoptotic effect of these growth factors have not been fully understood. This paper outlines the potential mechanisms underlying the augmented apoptosis during the erythroid differentiation in low-risk MDS as well as the anti-apoptotic effect of the growth factors.

Arsenic Trioxide in Patients With Myelodysplastic Syndromes: A Phase II Multicenter Study

Purpose

Evaluation of the safety and efficacy of arsenic trioxide in patients with myelodysplastic syndromes (MDS).

Patients and Methods

MDS patients diagnosed according to standard French-American-British criteria received a loading dose of 0.3 mg/kg per day of arsenic trioxide for 5 days followed by a maintenance dose of 0.25 mg/kg arsenic trioxide twice weekly for 15 weeks. Patients were divided into two cohorts: lower-risk MDS (International Prognostic Scoring System risk category low or intermediate 1) and higher-risk MDS (International Prognostic Scoring System risk category intermediate 2 or high). Modified International Working Group criteria were used for response evaluation.

Results

Of 115 patients enrolled and treated in the study, 67% of patients were transfusion dependent at baseline; median age was 68 years. Most treatment-related adverse events were mild to moderate. The overall rate of hematologic improvement (intent-to-treat) was 24 (19%) of 115, including one complete and one partial response in the higher-risk cohort. The hematologic response rates were 13 (26%) of 50 and 11 (17%) of 64 in patients with lower-risk and higher-risk MDS, respectively. Major responses were observed in all three hematologic lineages; 16% of RBC transfusion-dependent patients and 29% of platelet transfusion-dependent patients became transfusion independent. At data cut off, the median response duration was 3.4 months, with responses ongoing in nine patients.

Conclusion

Arsenic trioxide treatment consisting of an initial loading dose followed by maintenance therapy has moderate activity in MDS, inducing hematologic responses in both lower- and higher-risk patients. This activity combined with a manageable adverse effect profile warrants the additional study of arsenic trioxide, particularly in combination therapy, for the treatment of patients with MDS.

Biological and prognostic significance of chromosome 5q deletions in myeloid malignancies

The presence of del(5q), either as the sole karyotypic abnormality or as part of a more complex karyotype, has distinct clinical implications for myelodysplastic syndromes (MDS) and acute myeloid leukemia. The 5q- syndrome, a subtype of low-risk MDS, is characterized by an isolated 5q deletion and <5% blasts in the bone marrow and can serve as a useful model for studying the role of 5q deletions in the pathogenesis and prognosis of myeloid malignancies. Recent clinical results with lenalidomide, an oral immunomodulatory drug, have shown durable erythroid responses, including transfusion independence and complete cytogenetic remissions in patients with del(5q) MDS with or without additional chromosomal abnormalities. These results indicate that lenalidomide can overcome the pathogenic effect of 5q deletion in MDS and restore bone marrow balance. The data provide important new insights into the pathobiology of 5q chromosomal deletions in myeloid malignancies.

Classification and scoring systems in myelodysplastic syndromes: a retrospective analysis of 311 patients

The main objective of this study was to evaluate the role of the recent World Health Organization (WHO) classification for assessing prognosis in patients with myelodysplastic syndromes (MDS). To this effect, we analyzed the prognostic impact of the WHO and French-American-British (FAB) morphologic classifications and of four different scoring systems in a series of 311 patients with primary MDS diagnosed between October 1990 and June 2001. Both the FAB and WHO classifications identified groups with different prognoses (p<0.0001), those presenting refractory anemia (RA) and refractory anemia with ringed sideroblasts (RARS) showing the best prognosis. The WHO classification subdivided RA into RA with only red cell dysplasia, and refractory cytopenia with multilineage dysplasia (RCMD), and RARS into RARS plus refractory cytopenia with multilineage dysplasia and ringed sideroblast (RCMD-RS). In our population, we have shown that the two subtypes characterized by dysplasia affecting exclusively the erythroid population (RA and RARS) have a better prognosis, with a median survival of 122.2 and 81.9 months, respectively, than those with multilineage dysplasia (RCMD and RCMD-RS) with a median survival of 32.3 and 43.2 months, respectively. There were no significant differences in median survival comparing RA with RAS (p<0.95), or comparing RCMD with RSCMD (p<0.97). Besides, the four scoring systems discriminated our MDS patients in terms of survival, and an increase in prognostic capacity was achieved on adding the score to the morphological classifications. Risk scoring had a greater prognostic impact than the FAB and WHO classifications. Prognostic scoring systems may be an important tool for risk stratification in hematological practice, and add significance to morphological classification. Combined application of the WHO classification and score system is useful for improving the identification of patients with a poorer prognosis. The WHO classification establishes more homogeneous subcategories than the FAB classification and is also able to identify groups with different prognoses.

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.

Characterization of the hemopoietic defect in early stages of the myelodysplastic syndromes

Myelodysplasia (MDS) is a heterogeneous disorder characterised by bone marrow failure and progression to acute myeloid leukaemia where the molecular and cellular haematopoietic defects are poorly understood. To gain insight into this the pathogenesis of this condition, we analyzed gene expression profiles of bone marrow CD34+ stem/progenitor cells from patients with MDS at a early stage in the disease and compared them with profiles from CD34+ cells from age-matched controls and patients with non-MDS anaemia. Given the heterogeneity of early MDS, a surprisingly consistent finding was decreased expression of B-cell lineage affiliated genes in MDS patients compared to normal controls and samples with non-MDS anaemia. These findings were then confirmed in the original samples and further samples from a new MDS patient group by Taqman Real Time PCR. Flow cytometry on unfractionated marrow from independent samples also demonstrated reduced B-cell progenitors in MDS patients compared to normal controls. These novel findings suggest a common perturbation in early MDS haematopoiesis. They also provide the rationale for a larger study to evaluate the diagnostic utility of reduced B-cell progenitor number as a diagnostic biomarker of early low risk MDS which can pose a diagnostic challenge.

Prevalence of MDS subtypes in Shanghai, China: a comparison of the World Health Organization and French American British classifications

The prevalence of subtypes of the myelodysplastic syndromes (MDS) was determined in a prospective series of 176 patients presenting at 28 Shanghai hospitals. Diagnosis was established in a single laboratory, analyzing morphologic, immunophenotypic, and cytogenetic data, using the World Health Organization (WHO) revised classification and directly compared to the French American British (FAB) criteria. The median age at diagnosis for all cases was 53 years. There was a striking increase in the prevalence of RCMD in younger patients relative to other subtypes (WHO). The overall frequency of clonal cytogenetic abnormalities was 26.5% (WHO) and 31% (FAB). The most frequently encountered lesions were trisomy 8, del(20)q, del(7q), and del(5q). These results are consistent with previously reported age-dependent differences in MDS and a decreased frequency of del(5q) abnormalities between China and the West. These results also indicate that multilineage dysplasia is a prominent feature in MDS developing in younger individuals in Shanghai and suggest distinguishing between RCMD and RA may be important in the design of studies to further understand regional differences in subtype prevalence and to elucidate the pathogenesis of this complex and multifactorial disease.

Chronic exposure to benzene results in a unique form of dysplasia

Hematotoxicity following chronic benzene exposure has been recognized for over a century, although the mechanism remains unknown. We describe a novel form of bone marrow dysplasia in 23 workers exposed to high concentrations of benzene. Distinguishing features of benzene-induced dysplasia include: marked dyserythropoiesis, eosinophilic dysplasia and abnormal cytoplasmic granulation of neutrophilic precursors. Hematophagocytosis, stromal degeneration and bone marrow hypoplasia are also seen. Severe bone marrow dysplasia is frequently accompanied by clonal T cell expansion and alterations in T lymphocyte subsets. No clonal cytogenetic abnormalities were observed. These results suggest that autoimmune-mediated bone marrow injury is an early or predisposing event in the pathogenesis of benzene-induced persistent hematopoietic disease.

Advances in myelodysplastic syndrome: nursing implications of azacitidine

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, leading to bone marrow failure and peripheral blood cytopenias. MDS is difficult to diagnose because of the absence of symptoms in the early stage of the disease; it often is discovered accidentally during routine physical examinations or blood tests. The U.S. Food and Drug Administration approved azacitidine (Vidaza, Pharmion Corporation, Boulder, CO) for the treatment of MDS. Prior to the approval of azacitidine, no approved therapies were available for the treatment of MDS. Azacitidine is believed to exert its anticancer effects by induction of hypomethylation and cytotoxicity. In clinical studies, the most common adverse events during treatment with azacitidine included nausea, anemia, thrombocytopenia, vomiting, pyrexia, leukopenia, diarrhea, fatigue, injection-site erythema, constipation, neutropenia, and ecchymosis. To ensure proper treatment with azacitidine, nurses should have an understanding of dosage and administration guidelines, commonly observed adverse events, monitoring and care of adverse events, and monitoring of laboratory tests. Having a comprehensive understanding of MDS, its underlying disease characteristics, and current treatments will enable oncology nurses to provide optimal patient care.

Emerging drugs for the treatment of myelodysplastic syndrome

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal haematopoietic stem cell disorders characterised by ineffective haematopoiesis and an increased risk of developing acute myeloid leukaemia. At present, the only curative option is allogeneic stem cell transplantation. However, the majority of patients are not eligible for this therapy, due to excessive treatment-related morbidity and mortality or lack of a suitable donor. As a result, the need for alternative therapies is great. Our improved understanding of the molecular pathogenesis of MDS has resulted in several new promising therapeutic agents. This review will consider the rational development of new agents based on the molecular biology of MDS.

Drug insight: emerging new drugs in the treatment of myelodysplastic syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic stem cell disorders. Although the currently used classification schemes and prognostic algorithms, which are based predominantly on morphologic assessment of blood and marrow smears, have been shown to be valid for defining disease subgroups, they do not take into consideration the significant biological diversity of MDS. As the numerous pathophysiologic pathways that are involved in MDS are being unraveled, new molecular targets are being identified. Novel and targeted therapeutic agents, including inhibitors of farnesyltransferases and receptor tyrosine kinases, more potent thalidomide analogs and epigenetic therapies, have produced encouraging results and might offer durable benefits to patients with MDS. This review intends to provide a concise report on some of the most up-to-date therapies being investigated in MDS.

Decitabine in Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a heterogenous group of hematopoietic stem cell disorders that are multifactorial in their etiology. Aberrant DNA hypermethylation is now thought to be involved in MDS, as numerous tumor-suppressor genes have been identified that are silenced in these patients. Thus, the use of DNA methyltransferase inhibitors, such as 5-aza-2'-deoxycytidine (decitabine, Dacogen, MGI Pharma Inc, Bloomington, MN), for reversal of this process appears to be a rational intervention that may influence the course of the disease. Several phase I/II studies have been conducted using a low-dose schedule of decitabine in MDS patients. Based on these studies, decitabine appears to be effective and generally well tolerated, especially in those patients with worse prognostic indicators. Recent results of a phase III study also confirmed that patients treated with decitabine compared to standard supportive care had higher overall response rates and longer time to AML transformation. Decitabine appears to be a promising new therapy for the treatment of MDS; however, defining the optimal dosing schedule and exploring the possible use in combination with other agents such as the histone deacetylase inhibitors need further evaluation.

Rescue of early-stage myelodysplastic syndrome-deriving erythroid precursors by the ectopic expression of a dominant-negative form of FADD

Myelodysplastic syndromes (MDSs) are characterized by peripheral blood cytopenia including anemia. We have investigated the implication of the extrinsic pathway of apoptosis in MDS-ineffective erythropoiesis by in vitro expansion of erythroid precursors from early stage (low and intermediate-1 International Prognosis Scoring System [IPSS]) MDS, advanced stage (intermediate-2 IPSS) MDS, and control bone marrow samples. We have previously shown that Fas and its ligand were overexpressed in early stage MDS erythroid cells. Here, we show that caspase-8 activity is significantly increased, whereas the expression of death receptors other than Fas, including the type 1 receptor for tumor necrosis factor α (TNF-α) and the receptors for the TNF-related apoptosis-inducing ligand (TRAIL), DR4 and DR5, was normal. We also observed that the adapter Fas-associated death domain (FADD) was overexpressed in early stage MDS erythroid cells. Transduction of early stage MDS-derived CD34+ progenitors with a FADD-encoding construct increased apoptosis of erythroid cells and dramatically reduced erythroid burst-forming unit (BFU-E) growth. Transduction of a dominant-negative (dn) mutant of FADD inhibited caspase-8 activity and cell death and rescued BFU-E growth without abrogating erythroid differentiation. These results extend the observation that Fas-dependent activation of caspase-8 accounts for apoptosis of early stage MDS erythroid cells and demonstrate for the first time that FADD is a valuable target to correct ineffective erythropoiesis in these syndromes.

Myelodysplastic Syndrome

During the past 15 years, important progress has been made in the understanding of the biology and prognosis of myelodysplastic syndrome (MDS). MDS is a clonal disorder characterized by ineffective hematopoiesis, which can lead to either fatal cytopenias or acute myelogenous leukemia (AML). Risk-adapted treatment strategies were established because of the high median age (60-75 years) of the MDS patients and the individual history of the disease (number of cytopenias, cytogenetic changes, transfusion requirements). Allogeneic bone marrow transplantation currently offers the only potentially curative treatment, but this form of therapy is not available for the typical MDS patient, who is >60 years of age. Therapy with erythropoietin and G-CSF has improved the quality of life of selected patients. The development of small molecules directed against specific molecular targets with minimal adverse effects is the hope for the future. Innovative uses of immunomodulatory agents and the optimizing of cytotoxic treatment should continue to help in the treatment of MDS.

Models of granulocyte DNA structure are highly predictive of myelodysplastic syndrome

We have used statistical models based on Fourier transform-infrared spectra to differentiate between the DNA structure of normal granulocytes and those obtained from patients with myelodysplastic syndrome (MDS). The substantial degree of discrimination achieved between the two DNA groups is attributed to differences in the nucleotide base and backbone structures. These structural differences allowed for the development of a discriminant analysis model that predicted, with high sensitivity and specificity, which DNA came from normal granulocytes vs. granulocytes from MDS patients. The findings are a promising basis for developing a blood test to diagnose and predict the occurrence of MDS, for which there is currently a paucity of molecular markers.

The myelodysplastic syndrome(s): a perspective and review highlighting current controversies

The myelodysplastic syndrome (MDS) includes a diverse group of clonal and potentially malignant bone marrow disorders characterized by ineffective and inadequate hematopoiesis. The presumed source of MDS is a genetically injured early marrow progenitor cell or pluripotential hematopoietic stem cell. The blood dyscrasias that fall under the broad diagnostic rubric of MDS appear to be quite heterogeneous, which has made it very difficult to construct a coherent, universally applicable MDS classification scheme. A recent re-classification proposal sponsored by the World Health Organization (WHO) has engendered considerable controversy. Although the precise incidence of MDS is uncertain, it has become clear that MDS is at least as common as acute myelogenous leukemia (AML). There is considerable overlap between these two conditions, and the former often segues into the latter; indeed, the distinction between AML and MDS can be murky, and some have argued that the current definitions are arbitrary. Despite the discovery of several tantalizing pathophysiological clues, the basic biology of MDS is incompletely understood. Treatment at present is generally frustrating and ineffective, and except for the small subset of patients who exhibit mild marrow dysfunction and low-risk cytogenetic lesions, the overall prognosis remains rather grim. In this narrative review, we highlight recent developments and controversies within the context of current knowledge about this mysterious and fascinating cluster of bone marrow failure states.

New approaches to the treatment of myelodysplasia

The therapeutic dilemma that confronts the management of patients with myelodysplastic syndromes (MDS) is illustrated by the absence of a Food and Drug Administration-approved agent with an indication for this disease. Clinical heterogeneity and inadequate understanding of the disease pathobiology have limited progress in the development of novel therapeutics. Preclinical investigations indicate that reciprocal interaction between the malignant clone and the microenvironment serve to create a hostile milieu that reinforces ineffective blood cell production. Ineffective hematopoiesis, the hallmark of MDS, arises from impaired progenitor responsiveness to normal trophic signals and excess local generation of inhibitory cytokines, which promote accelerated apoptotic loss of progenitors and their progeny. Evidence to support this model derives from cytokine neutralization studies and the direct relationship between plasma tumor necrosis factor-alpha concentration and DNA oxidation and glutathione depletion in malignant CD34+ progenitors. Recent investigations indicate that angiogenic molecules generated by malignant myelomonocytic precursors represent integral diffusable signals that reinforce leukemia progenitor self-renewal while promoting the generation of proapoptotic cytokines and medullary angiogenic response. The potential for leukemia evolution is compounded by epigenetic events including methylation silencing of the p15 proto-oncogene or activating ras point mutations. Delineation of such biologic features that are central to the pathobiology of MDS provides a reliable framework for the development of novel therapeutics. Antiangiogenic agents in clinical testing include vascular endothelial growth factor (VEGF) receptor tyrosine kinase inhibitors, thalidomide and related analogues, and the recombinant VEGF neutralizing antibody, bevacizumab. Agents whose actions may restore differentiation programs, such as the DNA methyltransferase inhibitors or histone deacetylase inhibitors, offer the prospect to promote effective hematopoiesis while impacting the potential for leukemia evolution. RAS farnesyl transferase inhibitors have shown encouraging preliminary results in acute myeloid leukemia and are currently under investigation in advanced MDS and chronic myelomonocytic leukemia. Arsenic trioxide (ATO) interacts with a spectrum of biologic targets that may be uniquely suited to MDS. ATO is a potent inducer of apoptosis in thiol-depleted malignant progenitors and neovascular endothelium, while promoting differentiation through histone acetylation and inactivation of transcriptional corepressors. The identification of relevant biologic targets in MDS has raised expectations for the development of disease-specific therapies for MDS in the years that follow.

Targeting hypomethylation of DNA to achieve cellular differentiation in myelodysplastic syndromes (MDS)

Considerable progress has been made recently in defining and understanding the diverse members of the group of hematologic disorders now known as the myelodysplastic syndrome (MDS). New systems of classification, based on the latest cytogenetic methodologies, have generated better prognostic data, and basic research has more closely associated molecular mechanisms with clinical subgroups. The mechanisms underlying most cases of myelodysplasia appear to be an array of chromosomal abnormalities leading to suppression of normal myeloid cell differentiation and dominance of abnormal, immature cells. The process is progressive and is mediated by a variety of cytokines, potential loss of tumor suppressor genes, aberrations in signal transduction pathways, and perhaps immune mechanisms. Hypermethylation of specific DNA sequences has been implicated in the pathogenesis of MDS. Until recently, treatment options have been few, high risk, and mostly ineffective. New discoveries, particularly in the area of stimulating remaining normal myeloid cells to resume growth and differentiation, hold promise for safer treatment regimens and improved outcomes. Among the promising new agents are nucleoside analogues, such as 5-azacytidine and decitabine, which reactivate tumor suppressor gene transcription through effects on DNA methylation.

Diagnostic utility of flow cytometric immunophenotyping in myelodysplastic syndrome

The myelodysplastic syndromes (MDSs) are characterized by bilineage or trilineage dysplasia. Although diagnostic criteria are well established for MDS, a significant number of patients have blood and bone marrow findings that make diagnosis and classification difficult. Flow cytometric immunophenotyping is an accurate and highly sensitive method for detection of quantitative and qualitative abnormalities in hematopoietic cells. Flow cytometry was used to study hematopoietic cell populations in the bone marrow of 45 patients with straightforward MDS. The results were compared with those obtained in a series of patients with aplastic anemia, healthy donors, and patients with a history of nonmyeloid neoplasia in complete remission. The immunophenotypic abnormalities associated with MDS were defined, and the diagnostic utility of flow cytometry was compared, with morphologic and cytogenetic evaluations in 20 difficult cases. Although morphology and cytogenetics were adequate for diagnosis in most cases, flow cytometry could detect immunophenotypic abnormalities in cases when combined morphology and cytogenetics were nondiagnostic. It is concluded that flow cytometric immunophenotyping may help establish the diagnosis of MDS, especially when morphology and cytogenetics are indeterminate. (Blood. 2001;98:979-987)

Malignant hematopoietic cell lines: in vitro models for the study of myelodysplastic syndromes

The myelodysplastic syndromes (MDS) are clonal myeloid disorders characterized by bone marrow cell dysplasia and ineffective hematopoiesis leading to peripheral refractory cytopenias. The course of the disease ranges from a chronic status with progressively impaired hematopoiesis to rapid evolution to acute myeloid leukemia (AML). A panel of continuous malignant hematopoietic cell lines has been established from the whole spectrum of MDS variants and also from the different stages of the diseases, namely from the MDS phase or the overt leukemia post-MDS phase. Ten cell lines were derived from the various MDS subtypes; 17 cell lines were established from patients with leukemia (mainly AML) post-MDS. While most cell lines display myelocytic, monocytic or erythroid features, some cell lines carry lymphoid characteristics (precursor B-cell, B-cell, or T-cell), With regard to these lymphoid MDS-derived cell lines, more detailed authentication (prove of derivation from the assumed patient) and verification (prove of the malignant nature of the cell line and derivation from the assumed neoplastic cells) are required to validate the cell lines as true in vitro representatives of MDS and to exclude any cross-contamination with other cells or immortalization of normal bystander cells. On the other hand, lymphoid MDS-derived cell lines may attest to the clonal nature of MDS which may afflict progenitor cells giving rise to lymphoid or myelomonocytoid cells. Many of the MDS-derived cell lines carry cytogenetic and molecular genetic abnormalities typically associated with MDS: gain or loss of all or parts of chromosomes 5, 7, 8 and 20 (-5/5q-, -7/7q-, + 8, 20q-); alterations of oncogenes and tumor suppressor genes (IRF-1, p15, p16, p53, RAS, RB). In summary, the present panel of cell lines provides continuously growing cells and thus unlimited cell material for use as in vitro paradigms covering the whole spectrum of MDS-related hematopoetic malignancies. Properly authenticated and verified MDS-derived cell lines which should be made freely available will represent important research tools for the study of MDS biology.