Role of molecular alterations in transplantation decisions for patients with primary myelofibrosis.

The aim of our study was to analyze the potential survival benefit associated with HSCT according to clinico-biological scores which incorporate molecular data (MIPSS70 and MIPSS70+V2) to facilitate decision-making in this context. One transplant (n=241) and one non-transplant cohorts (n=239) were used to test the hypothesis that PMF patients with higher risk molecular score benefit from HSCT. A weighted propensity score was applied to balance confounding factors with the transplanted cohort as reference. Weighted Cox proportional hazard models and logistic regression analyses were performed. 105 non-transplanted patients could be matched to the 239 transplanted patients. Mean age in transplanted and non-transplanted matched patients was 55.5 and 57.9 years. Blood cell count and DIPSS score distribution were similar in both groups. HSCT was associated with a higher 6-year OS rate in intermediate-2 (60.1% versus 41.5%) and high-risk DIPSS patients (44.4% versus 6.55%), high-risk MIPSS70 (46.5 versus 23.9%), high-risk (73.2% versus 39.7%) or very high-risk MIPSS70V2 (51.8% versus 24%). Intermediate MIPSS70 patients have an advantage of survival with HSCT only when their MTSS were low or intermediate. Transplanted patients had an increased mortality risk the first year but a significant benefit with HSCT after the one-year landmark was observed in higher risk patients. This study confirms that similar to DIPSS, MIPSS70 and MIPSS70+V2 risk score in addition to MTSS can be used to determine which patients with primary myelofibrosis have survival benefit from HSCT over non-HSCT strategies.