Improving diagnostic and prognostic accuracy of myeloid neoplasms (MNs) by next generation sequencing.

Abstract

e18567 Background: Molecular aberrations in MNs have been well described. Driver mutations such as JAK2, MPL, and CALR, are pathognomonic for MNs, whereas other somatic mutations are less specific but have prognostic significance. Multi-gene panel testing for known somatic mutations has been utilized for diagnostic and prognostic purposes, and testing for somatic mutations to identify clonal hematopoiesis has been adopted by the WHO 2016 classification of myeloid malignancies. We sought to assess the impact of testing for somatic mutations by NGS on diagnosis and management of pts with MNs. Methods: We employed a myeloid panel (MP) of 40 commonly mutated genes involving RNA splicing, chromatin remodeling, and signaling pathways. Testing was performed on ptswho presented to the clinic between 2/2015 and 12/2016. Initial diagnosis and rationale for testing (diagnostic or prognostic) were recorded. We then determined whether the MP resulted in a change in diagnosis, prognosis, or management. Results: 55 pts with a known or suspected MN had a MP performed.Diagnoses at presentation were: MDS (27), MF (8), MPN-U (8), MDS/MPN (4), multiple diagnoses (2), and no definitive diagnosis of MN (6). 87% (48/55) of pts had at least one somatic mutation.In 13 pts (23.6%) the MP led to a definitive diagnosis or a change in diagnosis. For example, 2 pts initially diagnosed with MPN-U were diagnosed with CNL after detection of CSF3R mutation. All 4 pts initially diagnosed with MDS with fibrosis were subsequently diagnosed with primary myelofibrosis; 3 had a MPL mutation and 1 had a CALR mutation. Management was altered in 12 pts (21.8%) and prognosis was changed in 11 pts (20.0%). For example, 2 pts were treated with a JAK-2 inhibitor and 2 pts with low risk MDS were referred for transplant evaluation due to the presence of a TP53mutation. Conclusions: Our study confirms that panel testing meaningfully improves diagnostic accuracy and provides prognostic value. In total, the MP resulted in a change in diagnosis, prognosis, or management in 43.6% (24/55) of cases. Confirmation of these observations merits prospective evaluation for a larger number of pts.