Allogeneic hemopoietic SCT for patients with primary myelofibrosis: a predictive transplant score based on transfusion requirement, spleen size and donor type.

A total of 46 patients with primary myelofibrosis (PMF) (median age 51 years), underwent an allogeneic hemopoietic SCT (HSCT) after a thiotepa-based reduced-intensity conditioning regimen. The median follow-up for surviving patients is 3.8 years. In multivariate analysis, independent unfavorable factors for survival were RBC transfusions >20, a spleen size >22 cm and an alternative donor-24 patients had 0-1 unfavorable predictors (low risk) and 22 patients had 2 or more negative predictors (high risk). The overall actuarial 5-year survival of the 46 patients is 45%. The actuarial survival of low-risk and high-risk patients is, respectively, 77 and 8% (P<0.0001); this is because of a higher TRM for high-risk patients (RR, 6.0, P=0.006) and a higher relapse-related death (RR, 7.69; P=0.001). In multivariate Cox analysis, the score maintained its predictive value (P=0.0003), even after correcting for donor-patient age and gender, Dupriez score, IPSS (International Prognostic Scoring System) score pre-transplant and splenectomy. In conclusion, PMF patients undergoing an allogeneic HSCT may be scored according to the spleen size, transfusion history and donor type; this scoring system may be useful to discuss transplant strategies.