Contribution of comorbidities and grade of bone marrow fibrosis to the prognosis of survival in patients with primary myelofibrosis.

The widely used current International Prognostic Scoring System (IPSS) for primary myelofibrosis (PMF) is based on clinical parameters. The objective of this study was to identify additional prognostic factors at the time of diagnosis, which could have an impact on the future treatment of patients with PMF. We conducted a study of 131 consecutive PMF patients with median follow-up of 44 months. Data on baseline demographics, clinical and laboratory parameters, IPSS, grade of bone marrow fibrosis (MF), as well as influence of concomitant comorbidities were analyzed in terms of survival. Comorbidity was assessed using the Adult Comorbidity Evaluation-27 (ACE-27) score and the hematopoietic cell transplantation comorbidity index. An improved prognostic model of survival was obtained by deploying the MF and ACE-27 to the IPSS. A multivariable regression analyses confirmed the statistical significance of IPSS (P<0.001, HR 3.754, 95% CI 2.130-6.615), MF>1 (P=0.001, HR 2.694, 95% CI 1.466-4.951) and ACE-27 (P<0.001, HR 4.141, 95% CI 2.322-7.386) in predicting the survival of patients with PMF. When the IPSS was modified with MF and ACE-27, the final prognostic model for overall survival was stratified as low (score 0-1), intermediate (score 2-3) and high risk (score 4-6) with median survival of not reached, 115 and 22 months, respectively (P<0.001). Our findings indicate that the combination of histological changes, comorbidity assessment and clinical parameters at the time of diagnosis allows better discrimination of patients in survival prognostic groups and helps to identify high-risk patients for a poor outcome.