Prognostic indicators and scoring systems for predicting outcome in patients with myelodysplastic syndromes

A number of clinical, laboratory, morphological and genetic factors are useful to predict the natural course of Myelodysplastic syndromes (MDS). The identification of these factors resulted in the development of scoring systems that aid to differentiate high risk patients from those with a better prognosis. At the initial approach towards a patient with MDS the clinician will take into account the individual's age and performance score, and the morphological characteristics of the peripheral blood and bone marrow, including number of dysplastic lineages and blast count, as proposed by the new World Health Organization classification. Some laboratory features like the neutrophil and platelet count and the lactate dehydrogenase levels are of additional independent prognostic importance. Finally, the karyotype of the malignant hematopoietic cells is a very strong prognostic variable and therefore mandatory in the assessment of patients with MDS. By using part of the above-mentioned factors, the International Prognostic Scoring System has proven reliable in grouping MDS patients into one of four risk categories and can be used in the stratification of patients in therapeutic trials. With the avenue of more sophisticated molecular techniques like gene expression profiling, it might become possible not only to predict the natural course of the disease more precisely, but also to identify patient populations that are prone to respond to specific drugs especially designed for specific genetic lesions.