An Observational Study for Dacogen Long-Term Treatment in Patients With Myelodysplastic Syndrome

• overall response rate [ Time Frame: every 28 days up to approximately 5 years ] [ Designated as safety issue: No ]
  

• The change of transfusion requirements [ Time Frame: every 4 weeks up to approximately 5 years ] [ Designated as safety issue: No ]
  
• Overall survival [ Time Frame: every 3 months up to approximately 5 years ] [ Designated as safety issue: No ]
  
• Adverse events [ Time Frame: every 4 weeks up to approximately 5 years ] [ Designated as safety issue: Yes ]
  

This study is a prospective (the study follows a group of individuals over time), open label (all people involved know the identity of the intervention), multicenter, single arm (one group of patients receiving the same treatment), observational study to observe the response rate and safety of decitabine when treating patients with myelodysplastic syndrome with decitabine. Decitabine is to be administered as long as there is evidence of clinical benefit. It will be assessed if the treatment duration could be prolonged by appropriate toxicity management such as an active antibiotic prophylaxis or dose and schedule modification, and whether this leads to potentially increased clinical benefits such as higher response rate, longer time to Acute Myeloid Leukemia, and prolonged overall survival. For safety evaluation, adverse events and peripheral blood findings will be collected. The patient will receive decitabine intravenous injection 20mg/m2 once a day for 5 consecutive days every 4 weeks.