Since most cases of chronic myelomonocytic leukemia (CMML) have no known cause, this disease can rarely be prevented.
Treating cancer with chemotherapy and radiation may cause CMML. Doctors are studying ways to minimize the risk of CMML developing in patients receiving these treatments. In some cancers, doctors may try to avoid using the chemotherapy drugs that are more likely to lead to CMML. For certain cancers, however, these drugs may be needed. Often, the obvious benefits of treating life-threatening cancers with chemotherapy and radiation therapy must be balanced against the small chance of developing CMML several years later.