Concise Review of Chronic Myelomonocytic Leukemia in Canada in 2025

Chronic myelomonocytic leukemia (CMML) is a clonal myelodysplastic syndrome/myeloproliferative overlap neoplasm characterized by prominent monocytosis, with a very heterogeneous clinical presentation and an inherent risk of transforming to acute myeloid leukemia (AML). It is relatively rare, and the incidence is poorly defined. A Canadian analysis of a period of 20 years identified 1,440 cases and reported an incidence of 2.45 cases per 1,000,000. Given that it often presents at an advanced age, with a median age of 70–76 years, aggressive therapeutic approaches are limited.