IPSS-R and IPSS-M (myelodysplastic syndrome risk scores)

What is measured: the risk of progression to acute leukaemia and of death. How: IPSS-R (2012) scores marrow blast percentage, a five-tier cytogenetic category (very good to very poor), haemoglobin, platelets and neutrophils into five groups from very low to very high; IPSS-M (2022) keeps the clinical variables and adds mutations in 31 genes from a myeloid sequencing panel, including TP53 allelic state (multi-hit is far worse than single-hit), SF3B1 (favourable when isolated) and a count of residual mutated genes, giving six groups and moving about half of patients, most of them upwards. Inputs come from a marrow aspirate and trephine with blast count, karyotype and FISH (del(5q), monosomy 7 or del(7q), complex karyotype) and sequencing. What a result changes: lower-risk disease is managed for its cytopenias (erythropoiesis-stimulating agents, luspatercept, lenalidomide for del(5q), imetelstat, transfusion and iron chelation); higher-risk disease moves to hypomethylating agents and, when fit, allogeneic transplant, with the score deciding timing; both scores set trial eligibility. Where it matters: lower-risk and higher-risk MDS; DIPSS and MIPSS70 are the myelofibrosis equivalents and IPSSWM the Waldenström one.