Non-interventional multicentre retrospective study using chart reviews - study was submitted to the ethics committee of city of Vienna - due to the design of the study no specific approval necessary.~Inclusion of MDS (all subtypes and risk groups) patients according to WHO or oligoblastic AML (RAEB-T according to FAB), untreated and treated during their chronic MDS phase~The 26 centers of the IWG-PM have provided control data set of untreated, all centers will be asked for contribution of treated patients Data will be collected in Austria, Brazil, Czech Republic, France, Germany, Italy, Japan, Netherlands, Spain, UK, USA.
A comparison of treated vs untreated patients with MDS with a sample size of approximately 8000 patients in 11 countries.