Abstract
Risk stratification in primary myelofibrosis is currently based on two international prognostic scoring systems, neither of which takes into consideration red blood cell transfusion-dependency. In 288 consecutive patients with primary myelofibrosis, red blood cell transfusion-dependency at diagnosis affects survival independently of the International Prognostic Scoring System (P < 0.001). To evaluate the dynamic impact on survival of red blood cell transfusion-dependency, we performed a Cox's regression analysis with transfusion status as time-dependent covariate in 220 regularly followed patients with primary myelofibrosis. Patients who begin red blood cell transfusions anytime (n = 80, 36%) have a significantly worse survival compared to those who continue follow up without transfusions (HR: 7.8, 95%CI: 5.1-11.9; P < 0.001). Adjusting for Dynamic International Prognostic Scoring System in a multivariate analysis, red blood cell transfusion-dependency retained an independent prognostic impact on survival. This study suggests that red blood cell transfusion-dependency should be considered to improve risk stratification of primary myelofibrosis during follow up.