More than 80% of patients with PMF harbor DNA variants/mutations other than JAK2/CALR/MPL.
Some of these variants/mutations adversely affect overall or leukemia-free survival independent of conventional risk stratification.

Key Points

Abstract

A myeloid neoplasm–relevant 27-gene panel was used for next-generation sequencing of bone marrow or whole blood DNA in 182 patients with primary myelofibrosis (PMF). DNA sequence variants/mutations other than JAK2/CALR/MPL were detected in 147 patients (81%), with the most frequent being ASXL1 (36%), TET2 (18%), SRSF2 (18%), and U2AF1 (16%); furthermore, 35%, 26%, 10%, and 9% of the patients harbored 1, 2, 3, or 4 or more such variants/mutations, respectively. Adverse variants/mutations were identified by age-adjusted multivariable analysis of impact on overall survival or leukemia-free survival and included ASXL1, SRSF2, CBL, KIT, RUNX1, SH2B3, and CEBPA; their combined prevalence was 56%. Adverse variants/mutations were associated with inferior overall survival (median, 3.6 vs 8.5 years; P < .001) and leukemia-free survival (7-year risk, 25% vs 4%; P < .001), and the effect on survival was independent of both the Dynamic International Prognostic Scoring System Plus and JAK2/CALR/MPL mutational status, with respective hazard ratios of 2.0 (95% confidence interval [CI], 1.3-3.1) and 2.9 (95% CI, 1.9-4.4). Additional prognostic information was obtained by considering the number of adverse variants/mutations; median survivals in patients with zero (n = 80), 1 or 2 (n = 93), or 3 or more (n = 9) adverse variants/mutations were 8.5, 4, and 0.7 years, respectively (P < .001). Additional data were obtained on pattern of mutation co-segregation and phenotypic correlation, including significant associations between U2AF1 and JAK2 mutations (P = .04) and U2AF1 mutations and anemia (P = .003) and thrombocytopenia (P = .006). We conclude that DNA variants/mutations other than JAK2/CALR/MPL are prevalent in PMF and are qualitatively and quantitatively relevant in predicting overall and leukemia-free survival.

Abstract

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Acknowledgments

This study was supported in part by the Mayo Clinic Harvey-Yulman Charitable Foundation for Myelofibrosis Tissue Bank, by the Clinical Database of Molecular and Biological Abnormalities, and by the Henry J. Predolin Foundation for Research in Leukemia, Mayo Clinic, Rochester, MN.

Acknowledgments

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