Sex and degree of severity influence the prognostic impact of anemia in primary myelofibrosis: analysis based on 1109 consecutive patients

Anemia is one of the major risk factors for survival in primary myelofibrosis (PMF). Current prognostic models in PMF, including the International Prognostic Scoring System (IPSS) 1 , dynamic IPSS (DIPSS) 2 and DIPSS-plus 3 , all list hemoglobin level (Hb) of <10 g/dl as one of their risk variables. However, the 10 g/dl Hb threshold used in these prognostic models overlooks the significant difference in Hb levels between men and women, and, also assumes similar prognostic weight between moderate and severe anemia; in regards to the latter, for example, red cell transfusion need confers an additional point of prognostic adversity in DIPSS-plus, which is independent of and in addition to what is accounted for a hemoglobin level of <10 g/dl 3 . The “dose-dependent” prognostic effect of anemia, and the effect of sex on the selection of prognostically relevant Hb thresholds, has previously been recognized in myelodysplastic syndromes (MDS) 4 . In the current study, we examined the severity-stratified and sex-specific prognostic contribution of anemia in PMF, in the context of other relevant clinical, cytogenetic and molecular risk factors.