Anemia in Myelodysplastic Syndromes

ENRICO, ALICIA; FLORES, GABRIELA; KORNBLIHTT, LAURA; NUCIFORA, ELSA; BESTACH, YESICA; LARRIPA, IRENE; BELLI, CAROLINA

''Anemia: Prevalence, Risk Factors and Management Strategies

Nova Science Publishers, Inc

Lugar: New York; Año: 2014; p. 65 - 98

One of the most challenging problems in hematology is the heterogeneous group of disorders that were formally defined as Myelodysplastic Syndromes (MDS) by the French-American-British Cooperative Group in 1982. MDS are clonal disorders of hematopoietic stem cells with a propensity to leukemic evolution. Idiopathic MDS occur mainly in older persons with an incidence of 5 per 100,000 persons per year in the general population that increases to 20 to 50 per year after 60 years of age. The bone marrow is normo/hiper-cellular, displays various morphologic abnormalities and the stem cells show defective capacity for self-renewal and differentiation leading into an ineffective hematopoiesis. Most patients are initially asymptomatic, and their condition is incidentally discovered on a routine blood test. Approximately 80% of patients manifests with anemia at diagnosis, and this percentage is increased in parallel with the evolution of the disease, being one of the hallmarks. The anemia is frequently macrocytic but refractory to treatment with folate and vitamin B12. The clinical course of MDS is highly variable, ranging from stable disease over 10 years to death within a few months due to complications associated with their cytopenias or leukemic transformation. Since the development of the Bournemouth index in 1985, various scoring systems have been designed, based on clinical characteristic at presentation, in order to define prognostic subgroups. Anemia is well established as a negative prognostic factor. The International Prognostic Scoring System, the gold standard for risk assessment, has been recently revised (IPSS-R) where new clinical relevant cut-points for hemoglobin level were defined, among other changes. In our series of 578 (324 patients belong to the Argentinean MDS Registry) de novo MDS patients, the degree of anemia shows a good reproducibility and effectiveness to predict clinical outcome. Patients were distributed according to the IPSS-R cut-points for hemoglobin level into: 256 (44%) 10 g/dL, 191 (33%) 8-9.9 g/dL and 131 (23%) 8 g/dL, with median survival of 60, 35, and 19 months, and time to leukemic evolution (25%) of 66, 23 and 14 months, respectively (p0.001). The relationship between severe anemia and poor clinical outcome suggests that anemia initiates or exacerbates functional decline, particularly, involving cardiovascular disease which is one of the most common co-morbidity in MDS patients. Also, there is a high prevalence of patients with transfusion dependence who are prompt to develop secondary iron overload, associated with clinical organ dysfunction, increased risk of cardiac failure, and reduced survival. The great variability in the outcome of MDS complicates decision-making regarding therapies and prognostic characterization of individual patients is vital prior initiating treatment. The main objective in lower risk patients is improving the quality of life, and in higher risk patients is to extend the survival trying to modify the natural history of the disease. Accordingly, therapies vary from supportive care to intensive chemotherapy and stem cell transplantation. The degree of anemia is one of the major criterions for diagnosis, prognosis and to proper select type and timing of treatment in MDS patients.