Incidence of leukaemia in patients with primary myelofibrosis and RBC-transfusion-dependence.

Our study shows that in patients with PMF receiving RBC transfusions the 1- and 2-year actuarial probability of transforming to BP is 4Æ4% and 6Æ9% respectively. These data may be useful in counselling patients with PMF and suggest that RBC transfusion-dependent patients should be strictly monitored in view of an increased risk of AML evolution. This may also serve in the design of clinical trials.