The 2016 WHO classification recognized pre-fibrotic primary myelofibrosis (pre-PMF) as a distinct entity. Nevertheless, a prognostic model specific for pre-PMF is still lacking. Our aim was to identify the most relevant clinical, histological, and driver mutation information at diagnosis to evaluate outcomes in pre-PMF patients in the real-world setting. We firstly assessed the association between IPSS or DIPSS at diagnosis and response variables in 378 pre-PMF patients. A strict association was observed between IPSS and DIPSS and occurrence of death. Other analyzed endpoints were not associated with IPSS or DIPSS as thrombo-hemorrhagic events at diagnosis or during follow-up, or did not show a clinical plausibility, as transformation into acute leukemia or overt PMF. The only covariates which were significantly associated with death were diabetes and second neoplasia, and were therefore included in two different prognostic settings: the first based on IPSS at diagnosis [class 1 vs. 0, OR (95%CIs): 3.34 (1.85-6.04); class 2 vs. 0, OR (95%CIs): 12.55 (5.04-31.24)], diabetes [OR (95%CIs): 2.95 (1.41-6.18)], and second neoplasia [OR (95%CIs): 2.88 (1.63-5.07)]; the second with DIPSS at diagnosis [class 1 vs. 0, OR (95%CIs): 3.40 (1.89-6.10); class 2 vs. 0, OR (95%CIs): 25.65 (7.62-86.42)], diabetes [OR (95%CIs): 2.89 (1.37-6.09)], and second neoplasia [OR (95%CIs): 2.97 (1.69-5.24)]. In conclusion, our study underlines the importance of other additional risk factors, such as diabetes and second neoplasia, to be evaluated, together with IPSS and DIPSS, to better define prognosis in pre-PMF patients.
Keywords: DIPSS; IPSS; diabetes; pre-fibrotic; primary myelofibrosis; prognosis; scoring system; second neoplasia.