title: Prognostic irrelevance of ring sideroblast percentage in World Health Organization-defined myelodysplastic syndromes without excess blasts.
abstract: The presence of ≥ 15% bone marrow (BM) ring sideroblasts (RS) and < 5% blasts is required for a diagnosis of refractory anemia with ring sideroblasts. We examined the phenotypic and prognostic relevance of this "15%" RS threshold in 200 patients with myelodysplastic syndromes (MDS) without excess blasts and with ≥ 1% RS. The impact of RS% was assessed both as a continuous and categorical variable: < 5% (n = 56), 5%-14% (n = 32), 15%-50% (n = 79), and > 50% (n = 33). RS% correlated (P < .05) directly with age, platelet count, transfusion dependency, BM cellularity, and mutant SF3B1 and inversely with hemoglobin level, multilineage dysplasia, and high-risk karyotype; but did not correlate with IDH mutations. At a median follow-up of 33 months, 156 (73%) deaths and 24 (12%) leukemic transformations were documented. Neither univariate nor multivariable analysis showed significant effect for RS% on overall or leukemia-free survival, suggesting the limited prognostic value of quantifying BM RS in MDS.
authors.affiliation: Division of Hematology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: Mrinal M
authors.initials: MM
authors.lastname: Patnaik
authors.forename: Curtis A
authors.initials: CA
authors.lastname: Hanson
authors.forename: Nanna H
authors.initials: NH
authors.lastname: Sulai
authors.forename: Janice M
authors.initials: JM
authors.lastname: Hodnefield
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Knudson
authors.forename: Rhett P
authors.initials: RP
authors.lastname: Ketterling
authors.forename: Terra L
authors.initials: TL
authors.lastname: Lasho
authors.forename: Ayalew
authors.initials: A
authors.lastname: Tefferi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000756:Anemia, Sideroblastic / Q000175:diagnosis*; D001752:Blast Crisis / Q000175:diagnosis* / Q000473:pathology*; D001853:Bone Marrow / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009190:Myelodysplastic Syndromes / Q000175:diagnosis* / Q000473:pathology*; D011379:Prognosis; D014944:World Health Organization; D055815:Young Adult