Myelodysplastic syndromes (MDS) are relatively rare, affecting fewer than four in 100,000 people. The risk for developing MDS increases with age; most patients are diagnosed in their 70s. About 12,000 new cases of MDS are diagnosed each year in the U.S. Most patients are men, and about 80% of all patients are older than 60.
About 10% of MDS cases develop after a patient has been treated with chemotherapy or radiation for another type of cancer — often breast, prostate or lung. Those treatments can damage the bone marrow, which can lead to MDS. However, the vast majority of cases occur as a result of other risk factors, including:
- Cigarette smoking
- Long-term exposure to benzene or other chemicals, such as toluene and xylene
- Exposure to pesticides
- A rare congenital disease called Fanconi anemia
- Inherited disorders such as Shwachman-Diamond syndrome, familial platelet disorder or severe congenital neutropenia
Keep in mind that having one or more risk factors does not mean you will develop MDS. Most people who have risk factors never develop the disease.