All trans retinoic acid with low dose cytosine arabinoside in the treatment of myelodysplastic syndrome

Chronic myelomonocytic leukemia prognostic classification and management: evidence base and current practice

Chronic myelomonocytic leukemia is a clonal malignancy of the ageing hematopoietic stem cell characterized by a biased differentiation leading to persistent monocytosis and inconstant hypersensitivity of myeloid progenitors to granulo-monocyte colony-stimulating factor (GM-CSF). Cytogenetic abnormalities identified in 30-40 % of patients and gene mutations detected in every patient can be used to stratify patients into risk groups that guide the therapeutic choices. TET2, SRSF2, ASXL1, and genes of the Ras pathway are the most frequently mutated genes, with ASXL1 mutations negatively affecting the disease outcome. Allogeneic stem cell transplantation is the first option to consider, especially in younger patients with poor prognostic factors. There is no firm clinical guideline in transplant-ineligible patients, but hypomethylating agents might be an interesting option. A consensus prognostic scoring system and specific response criteria are now required to facilitate the evaluation of new therapeutic strategies in clinical trials specifically dedicated to this disease.

Prolonged survival with improved tolerability in higher-risk myelodysplastic syndromes: azacitidine compared with low dose ara-C

In the phase III AZA-001 trial, low-dose cytarabine (LDara-C), the most widely used low-dose chemotherapy in patients with higher-risk myelodysplastic syndrome (MDS) who are ineligible for intensive treatment, was found to be associated with poorer survival compared with azacitidine. This analysis further compared the efficacy and the toxicity of these two drug regimens. Before randomization, investigators preselected patients to receive a conventional care regimen, one of which was LDara-C. Of 94 patients preselected to LDara-C, 45 were randomized to azacitidine and 49 to LDara-C. Azacitidine patients had significantly more and longer haematological responses and increased red blood cell transfusion independence. Azacitidine prolonged overall survival versus LDara-C in patients with poor cytogenetic risk, presence of -7/del(7q), and French-American-British subtypes refractory anaemia with excess blasts (RAEB) and RAEB in transformation. When analyzed per patient year of drug exposure, azacitidine treatment was associated with fewer grade 3-4 cytopenias and shorter hospitalisation time than LDara-C in these higher-risk MDS patients.

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.

Pathogenesis, classification, and treatment of myelodysplastic syndromes (MDS)

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal myeloid disorders characterized by morphologic dysplasia in one or more cell lineages. Dysplasia in MDS is associated with insufficient production of blood cells and consecutive cytopenia(s). The natural course and prognosis of MDS vary among patients and depend on genetic defects that occur during clonal evolution. In a significant group of patients (roughly 30%) progression to secondary leukemia is observed. These patients appear to have a grave prognosis. The treatment of patients with MDS has to be adjusted to the individual situation and age in each case. In many patients, control of blast cell production by palliative cytoreduction, continuous support with red blood cells, as well as other supportive measures, seem appropriate. In other patients, however, curative therapy (chemotherapy, stem cell transplantation) should be considered. The final decision to offer curative therapy must be based on many different factors including age and the overall situation of the patient. Recently established scoring systems aimed at predicting survival and evolution of leukemia in MDS may be helpful in this regard.

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.

The biologic basis for the use of retinoids in cancer prevention and treatment

Retinoids (vitamin A and related molecules) are biologic agents that have demonstrated, in preclinical and clinical models, potent activity in the prevention and treatment of a variety of malignancies. Presented in this article is a review of recent clinical studies and correlative laboratory findings that advance our understanding of the biologic basis for the use of retinoids in cancer prevention and treatment.