Clinico-biological characteristics of patients with myelofibrosis: an analysis of 1,000 cases from the Spanish Registry of Myelofibrosis

BACKGROUND AND OBJECTIVE MYELOFIBROSIS: is an infrequent chronic myeloproliferative neoplasm. We aimed to describe the clinico-biological characteristics, treatment, and evolutive course of myelofibrosis patients in Spain. MATERIAL AND METHODS:A total of 1,000 patients from the Spanish Registry of Myelofibrosis diagnosed with primary (n=641) or secondary (n=359) myelofibrosis were analysed. RESULTS:Median age was 68 years. The frequency of constitutional symptoms, moderate to severe anaemia (Hb<10g/dL), and symptomatic splenomegaly was 35%, 36%, and 17%, respectively. The rate of thrombosis and haemorrhage was 1.96 and 1.6 events per 100 patient-years, respectively. The cumulative incidence of leukaemia at 10 years was 15%. The most frequent therapies for the anaemia were the erythropoiesis stimulating agents and danazol. From 2010, a progressive increase in the use of ruxolitinib was noticed. A total of 7.5% of patients were transplanted. During the observation period, 42% of patients died mainly due to the clinical deterioration caused by myelofibrosis or leukaemic transformation. The median survival of the series was 5.7 years. Four different risk categories were identified by the IPSS: median survival was not reached in the low risk group and was 8.8 years, 5.3 years, and 2.8 years in the intermediate-1, intermediate-2, and high-risk groups, respectively. CONCLUSIONS:Myelofibrosis is a disabling condition mainly affecting elderly people. Its treatment is mostly driven by symptom control. Despite its clinical heterogeneity, several prognostic models are useful to select candidates for transplantation.