Utility of Next Generation Sequencing in the Workup and Diagnosis of Myeloproliferative neoplasm in the Peripheral Blood: A single institution experience

Abstract

Abstract Introduction/Objective In patients with suspicion of Myeloproliferative neoplasm (MPN) and negative for BCR-ABL1, NCCN guideline currently recommends two molecular workup pathways in peripheral blood: 1) a multi-step reflex mutation testing algorithm including JAK2 V617F, CALR, MPL, JAK2 exon12 or 2) a multigene Next Generation Sequencing (NGS) panel that includes at least JAK2, CALR and MPL genes. Here we report the clinical utilization and impact of a NGS based MPN diagnosis assay. Methods/Case Report Total of 690 consecutive cases at Geisinger between 2019 and 2021 were included in this study. Patient’s CBC showed chronic cytosis in either single or multi-lineage myelopoiesis and was clinically suspicious for MPNs. For BCR-ABL1 negative cases, NGS based MPN diagnostic assay was performed, which include the four disease defining genes recommended by NCCN guideline: JAK2, CALR, MPL, CSF3R as well as three additional genes NRAS, PPM1D and TP53. Variants are classified in to four tiers based on their level of clinical significance. Results (if a Case Study enter NA) Among all cases tested, 25 out of 690 cases (3.6%) were positive for BCR-ABL1 transcript. 20.9% (139 out of 665 BCR-ABL1 negative cases) had at least one variant detected, which included 73 variants in Tier I category (11.0%), 6 variants in Tier II (0.9%), 57 variants in Tier III (8.6%) and 3 variants in Tier IV(0.5%). Among all disease defining mutations, JAK2 V617F was the most commonly detected mutation (59 cases and 8.8%), followed by CALR indel mutations (13 cases and 2.0%). In addition, double variants were detected in total 7 cases (1.0%). Conclusion Comparing to the conventional multi-step sequential workup for MPN diagnosis, the multi-gene NGS panel provides a cost-effective and time- saving solution. When detected concurrently with the disease defining mutations, NRAS, PPM1D and TP53 could provide not only additional prognostic information but also may suggest pending progression in myeloproliferative neoplasms.