Prognostic factors in idiopathic myelofibrosis: A simple scoring system with prognostic significance

Abstract: In a prognostic univariate analysis of a series of 80 patients with idiopathic myelofibrosis the Hb‐concentration, the platelet count and osteomyelosclerosis emerged as factors with prognostic significance. A Hb‐concentration < 10 g/dl was associated with a significantly shorter survival than a Hb‐concentration ≥ 10 g/dl. A platelet count < 100 × 10⁹/1 also implied a significantly shorter survival. Patients with osteomyelosclerosis on X‐ray of the skeleton had a significantly better prognosis as compared to those without osteomyelosclerosis. In a multivariate regression analysis the Hb‐concentration consistently emerged as an important prognostic parameter, whereas the platelet count was only of prognostic significance within the first 6 months from diagnosis and the presence of osteomyelosclerosis emerged as a favourable parameter at 3 and 5 years. Based upon the above parameters and spleen size, a prognostic scoring system was designed which categorized the patients into three prognostic groups with highly different survival times (low risk group = 69 months; intermediate risk group = 33 months; high risk group = 4 months).