Analytical validation and performance characteristics of a 48-gene next-generation sequencing panel for detecting potentially actionable genomic alterations in myeloid neoplasms

Precision Diagnostics in Myeloid Malignancies: Development and Validation of a National Capture-Based Gene Panel

Gene panel sequencing has become a common diagnostic tool for detecting somatically acquired mutations in myeloid neoplasms. However, many panels have restricted content, provide insufficient sensitivity levels, or lack clinically validated workflows. We here describe the development and validation of the Genomic Medicine Sweden myeloid gene panel (GMS-MGP), a capture-based 191 gene panel including mandatory genes in contemporary guidelines as well as emerging candidates. The GMS-MGP displayed uniform coverage across all targets, including recognized difficult GC-rich areas. The validation of 117 previously described somatic variants showed a 100% concordance with a limit-of-detection of a 0.5% variant allele frequency (VAF), achieved by utilizing error correction and filtering against a panel-of-normals. A national interlaboratory comparison investigating 56 somatic variants demonstrated highly concordant results in both detection rate and reported VAFs. In addition, prospective analysis of 323 patients analyzed with the GMS-MGP as part of standard-of-care identified clinically significant genes as well as recurrent mutations in less well-studied genes. In conclusion, the GMS-MGP workflow supports sensitive detection of all clinically relevant genes, facilitates novel findings, and is, based on the capture-based design, easy to update once new guidelines become available. The GMS-MGP provides an important step toward nationally harmonized precision diagnostics of myeloid malignancies.

Expanding individualized therapeutic options via genoproteomics

Clinical next-generation sequencing (NGS)² tests have enabled treatment recommendations for cancer patients with driver gene mutations. Targeted therapy options for patients without driver gene mutations are currently unavailable. Herein, we performed NGS and proteomics tests on 169 formalin-fixed paraffin-embedded (FFPE)³ samples of non-small cell lung cancers (NSCLC, 65),⁴ colorectal cancers (CRC, 61),⁵ thyroid carcinomas (THCA, 14),⁶ gastric cancers (GC, 2),⁷ gastrointestinal stromal tumors (GIST, 11),⁸ and malignant melanomas (MM, 6).⁹ Of the 169 samples, NGS detected 14 actionable mutated genes in 73 samples, providing treatment options for 43% of the patients. Proteomics identified 61 actionable clinical drug targets approved by the FDA or undergoing clinical trials in 122 samples, providing treatment options for 72% of the patients. In vivo experiments demonstrated that the Mitogen-Activated Protein Kinase (MEK)¹⁰ inhibitor induced the overexpression of MEK1 (Map2k1) to block lung tumor growth in mice. Therefore, protein overexpression is a potentially feasible indicator for guiding targeted therapies. Collectively, our analysis suggests that combining NGS and proteomics (genoproteomics) could expand the targeted treatment options to 85% of cancer patients.

Genomic Alterations, Gene Expression Profiles and Functional Enrichment of Normal-Karyotype Acute Myeloid Leukaemia Based on Targeted Next-Generation Sequencing

Characterising genomic variants is paramount in understanding the pathogenesis and heterogeneity of normal-karyotype acute myeloid leukaemia (AML-NK). In this study, clinically significant genomic biomarkers were ascertained using targeted DNA sequencing and RNA sequencing on eight AML-NK patients' samples collected at disease presentation and after complete remission. In silico and Sanger sequencing validations were performed to validate variants of interest, and they were followed by the performance of functional and pathway enrichment analyses for overrepresentation analysis of genes with somatic variants. Somatic variants involving 26 genes were identified and classified as follows: 18/42 (42.9%) as pathogenic, 4/42 (9.5%) as likely pathogenic, 4/42 (9.5%) as variants of unknown significance, 7/42 (16.7%) as likely benign and 9/42 (21.4%) as benign. Nine novel somatic variants were discovered, of which three were likely pathogenic, in the CEBPA gene with significant association with its upregulation. Transcription misregulation in cancer tops the affected pathways involving upstream genes (CEBPA and RUNX1) that were deregulated in most patients during disease presentation and were closely related to the most enriched molecular function gene ontology category, DNA-binding transcription activator activity RNA polymerase II-specific (GO:0001228). In summary, this study elucidated putative variants and their gene expression profiles along with functional and pathway enrichment in AML-NK patients.

Gene mutation analysis using next-generation sequencing and its clinical significance in patients with myeloid neoplasm: A multi-center study from China

BACKGROUND

Myeloid neoplasms (MN) tend to relapse and deteriorate. Exploring the genomic mutation landscape of MN using next-generation sequencing (NGS) is a great measure to clarify the mechanism of oncogenesis and progression of MN.

METHODS

This multicenter retrospective study investigated 303 patients with MN using NGS from 2019 to 2021. The characteristics of the mutation landscape in the MN subgroups and the clinical value of gene variants were analyzed.

RESULTS

At least one mutation was detected in 88.11% of the patients (267/303). TET2 was the most common mutation in the cohort, followed by GATA2, ASXL1, FLT3, DNMT3A, and TP53. Among patients with myeloid leukemia (ML), multivariate analysis showed that patients aged ≥60 years had lower overall survival (OS, p = 0.004). Further analysis showed TET2, NPM1, SRSF2, and IDH1 gene mutations, and epigenetic genes (p < 0.050) presented significantly higher frequency in older patients. In patients with myelodysplastic syndrome (MDS) and myelodysplastic neoplasms (MPN), univariate analysis showed that BCORL1 had a significant impact on OS (p = 0.040); however, in multivariate analysis, there were no factors significantly associated with OS. Differential analysis of genetic mutations showed FLT3, TP53, MUC16, SRSF2, and KDM5A mutated more frequently (p < 0.050) in secondary acute myeloid leukemia (s-AML) than in MDS and MPN. TP53, U2AF1, SRSF2, and KDM5A were mutated more frequently (p < 0.050) in s-AML than in primary AML. KDM5A was observed to be restricted to patients with s-AML in this study, and only co-occurred with MUC16 and TP53 (2/2, 100%). Another mutation was MUC16, and its co-occurrence pattern differed between s-AML and AML. MUC16 mutations co-occurred with KDM5A and TP53 in 66.7% (2/3) of patients with s-AML and co-occurred with CEBPA in 100% (4/4) of patients with AML.

CONCLUSIONS

Our results demonstrate different genomic mutation patterns in the MN subgroups and highlight the clinical value of genetic variants.

Clinical Utility of Implementing a Frontline NGS-Based DNA and RNA Fusion Panel Test for Patients with Suspected Myeloid Malignancies

BACKGROUND

The use of molecular genetic biomarkers is rapidly advancing to aid diagnosis, prognosis, and clinical management of hematological disorders. We have implemented a next-generation sequencing (NGS) assay for detection of genetic variants and fusions as a frontline test for patients suspected with myeloid malignancy. In this study, we summarize the findings and assess the clinical impact in the first 1613 patients tested.

METHODS

All patients were assessed using NGS based Oncomine Myeloid Research Assay (ThermoFisher) including 40 genes (17 full genes and 23 genes with clinically relevant "hotspot" regions), along with a panel of 29 fusion driver genes (including over fusion 600 partners).

RESULTS

Among 1613 patients with suspected myeloid malignancy, 43% patients harbored at least one clinically relevant variant: 91% (90/100) in acute myeloid leukemia patients, 71.7% (160/223) in myelodysplastic syndrome (MDS), 77.5% (308/397) in myeloproliferative neoplasm (MPN), 83% (34/41) in MPN/MDS, and 100% (40/40) in chronic myeloid leukemia patients. Comparison of NGS and cytogenetics results revealed a high degree of concordance in gene fusion detection.

CONCLUSIONS

Our findings demonstrate clinical utility and feasibility of integrating a NGS-based gene mutation and fusion testing assay as a frontline diagnostic test in a large reported cohort of patients with suspected myeloid malignancy, in a clinical laboratory setting. Overlap with cytogenetic test results provides opportunity for testing reduction and streamlining.