Myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis: Ringing in a new future. (April 2022) - Nathan, Daniel I.
Abstract: Myelodysplastic syndrome/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/MPN-RS-T) is a rare hematologic malignancy belonging to the category of myelodysplastic syndrome (MDS)/myeloproliferative neoplasm (MPN) overlap syndromes. While certain clinical features, including anemia and thrombocytosis, are common to both the MDS and MPN disease components, the biologic consequences of the spliceosome mutation SF3B1 results in notable clinical exceptions. Importantly, both overall and leukemia free survival are shorter for MDS/MPN-RS-T when compared to essential thrombocythemia (ET). In the case of MDS/MPN-RS-T, thrombotic risk is not associated with the presence of JAK2V617F, nor history of prior thrombosis, but is associated with the presence of the mutated spliceosome gene SF3B1. In this review, we highlight the biology, pathology, risk stratification, and treatment approach to MDS/MPN-RS-T. In particular, we focus on clinical management concepts, which are largely borrowed from MDS and MPN, including the use of cytoreduction, bone marrow stimulating agents, and the role of allogeneic stem cell transplantation. We end by highlighting unmet needs and future research priorities in MDS/MPN-RS-T. Highlights: MDS/MPN-RS-T is a rare overlap syndrome with features of MDS and MPN. Spliceosome mutations in SF3B1 are common and result in unique clinical features. Overall survival and leukemia free survival are shortened when compared with ET. Thrombotic risk is associated with mutant SF3B1 but not JAK2V617F. Therapeutic data is sparse and largely borrowed from the MDS and MPN literature.