There are several different types of myelodysplastic syndromes, and life expectancy varies on a case-by-case basis. Patients undergoing treatment for lower-risk types of myelodysplastic syndrome live for five years or longer. Higher-risk cases have a shorter life expectancy, according to the Aplastic Anemia & MDS International Foundation.
Doctors evaluate a patient and give a prognosis based on the International Prognostic Scoring System, or IPSS. The system focuses on three aspects of the patient's condition: chromosome changes in bone marrow cells, low blood counts and percentage of young white blood cells in marrow. Approximately 30 percent of MDS patients progress to acute myeloid leukemia, according to the Aplastic Anemia & MDS International Foundation.