Myelodysplastic syndromes in adults aged less than 50 years: incidence and clinicopathological data.

PURPOSE Myelodysplastic syndrome (MDS) is rarely seen in patients younger than 50 years, but rapidly increases with advancing age. Data on MDS biology in young patients are yet scarce but more than necessary. The purpose of this study was to estimate the proportion of MDS patients <50 years of age and to compare the clinicopathological data between younger and older patients. METHODS Of our total MDS cases comprising 587 adult patients we studied 83 adults (14.14%) aged < 50 years with primary MDS. RESULTS MDS patients were classified in those aged < 50 years and those aged ≥ 50 years. Younger MDS patients were characterized by female preponderance (p<0.001), better performance status (p=0.0035), less severe anaemia (p=0.008), better preserved kidney function (p=0.037), less often blast infiltration in bone marrow (p=0.015), more cases of RA (p<0.001) and RCUD (p=0.0066), lower MD Anderson score (p<0.001), longer overall survival (OS) (p<0.001), but similar progression rate (p=0.591). Median OS of young MDS patients was 39.7 months and 19 months of patients >50 years (p<0.001). In this group, 24 patients (28.92%) progressed to acute myeloid leukaemia (AML) vs 111 (22.02%) patients>50 years (p=0.402). Multivariate analysis identified platelet count (p=0.008) and percent of blasts in bone marrow (p=0.024) to be predictive for shorter OS in patients < 50 years of age; the same factors (p<0.001) together with IPSS-R cytogenetic risk group (p<0.001) were identified in patients >50 years of age. Platelet count (p=0.003) and percent of blasts in bone marrow (p=0.001) were predictive for higher risk of transformation to AML in patients <50 years, and bone marrow infiltration (p=0.022) and IPSS-R cytogenetic risk group (p=0.027) for patients >50 years of age. CONCLUSION Presenting features in young MDS patients may identify subjects at higher risk for unfavorable outcome.