I walk the other line: myelodysplastic/myeloproliferative neoplasm overlap syndromes

Patients with the myelodysplastic syndromes/myeloproliferative neoplasm (MDS/MPN) overlap, including chronic myelomonocytic leukemia (CMML), atypical chronic myeloid leukemia (aCML), MDS/MPN-unclassifiable (MDS/MPN-U), and refractory anemia with ring sideroblasts associated with marked thrombocytosis (RARS-T), often present with findings of both dysplasia and marrow proliferation, occupying the border region of two seemingly divergent camps. Historically, these disorders which have been lumped with either MDS or MPN have represented a minority, or been excluded all together, from the development of prognostic models and clinical trials. Therefore, Food and Drug Administration approved therapies specifically for overlap subtypes are lacking. More recently, the revolution in molecular genetics has led to discovery of mutations enacting pathways that result in the distinct biology and presentation of the overlap syndromes. Additionally, these recurrent genetic lesions have a prognostic value and are potential therapeutic targets, which might ultimately improve patient outcomes by reducing disease-related symptoms and complications and by prolonging survival.