Currently available prognostic scoring systems in primary myelofibrosis (PMF) do not integrate clinical, histological, and molecular data, or they also required information on "other" mutations that are available in the clinical practice only in a very limited number of laboratories. In the present multicenter study, including 401 PMF patients, an integrated International Prognostic Scoring System (I-IPSS) was developed by combining IPSS, grade of bone marrow fibrosis (GBMF), and driver mutations molecular status (MS) to define PMF prognosis at diagnosis. Four prognostic categories were identified: I-IPSS-low risk (113 patients), I-IPSS-intermediate-1 risk (56 patients), I-IPSS-intermediate-2 risk (154 patients), and I-IPSS-high risk (78 patients). Median overall survival was 26.7 years in I-IPSS-intermediate-1, 10.8 in I-IPSS-intermediate-2, and 6.4 in I-IPSS-high-risk patients (log-rank test <0.0001); instead, it was not reached in the I-IPSS-low-risk cohort because of the extremely low number of registered deaths. The addition of GBMF and MS to IPSS improved the efficacy for predicting the risk of death. Indeed, the sensitivity of I-IPSS was significantly higher (P < .05) than that of IPSS, considering both total deaths and 5- and 10-year mortality. This comprehensive approach allows clinicians to evaluate mutual interactions between IPSS, GBMF, and MS and identify high-risk patients with poor prognosis who may benefit from aggressive treatments. More importantly, this integrated score can be easily applicable worldwide as it only required information that represent the good clinical practice in the management of PMF patients.
Keywords: bone marrow fibrosis; driver mutations; primary myelofibrosis; prognosis; risk categories.
© 2019 John Wiley & Sons, Ltd.