Related Experiment Video
Updated: Feb 24, 2026
Detection of Targetable Alterations in Non-small Cell Lung Cancer using Next-generation Sequencing
Published on: October 10, 2025
Somatic mutation analysis in melanoma using targeted next generation sequencing
Allen P Miraflor1, Francine B de Abreu1, Jason D Peterson1
1Department of Pathology and Laboratory Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756, United States.
Abstract:
Advanced stage malignant melanoma often responds poorly to therapy with low survival rates. New therapeutic approaches are based upon a growing understanding of the underlying molecular abnormalities. We demonstrate the feasibility of a next generation sequencing (NGS) assay, which targets hotspots in 50 cancer genes, to assess genotypes that may influence therapeutic selection and response. DNA was extracted from formalin fixed paraffin embedded (FFPE) melanoma specimens to create multiplexed libraries which were sequenced. Of the 121 cases, BRAF mutations were present in 48 cases (40%) and NRAS mutations in 24 cases (20%). We identified other gene variants in 20 BRAF-mutated cases. Additional gene variants were also identified in the 57 BRAF wild-type cases. Four patients harbored different gene mutations at metastatic sites as compared to their primary lesions or metastasis from different sites. Concurrent gene variants may provide additional targets for future therapies and may suggest alternative mechanisms of secondary resistance.
Insights
This study shows a new genetic test for advanced melanoma. The next-generation sequencing assay identifies mutations like BRAF and NRAS, guiding personalized cancer therapy and predicting treatment response.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Advanced stage malignant melanoma has poor therapeutic response and low survival rates.
- Understanding molecular abnormalities is key to developing new melanoma treatments.
- Personalized medicine approaches require detailed genotypic information.
Purpose of the Study:
- To demonstrate the feasibility of a next-generation sequencing (NGS) assay for assessing melanoma genotypes.
- To identify genetic variants influencing therapeutic selection and response in melanoma patients.
- To evaluate the utility of NGS in detecting actionable mutations and resistance mechanisms.
Main Methods:
- DNA extraction from formalin-fixed paraffin-embedded (FFPE) melanoma specimens.
- Development and application of a multiplexed next-generation sequencing (NGS) assay targeting 50 cancer gene hotspots.
- Sequencing of 121 melanoma cases to identify gene variants.
Main Results:
- BRAF mutations were detected in 40% (48/121) and NRAS mutations in 20% (24/121) of cases.
- Other gene variants were identified in 20 BRAF-mutated and 57 BRAF wild-type cases.
- Four patients exhibited distinct mutations in metastatic sites compared to primary lesions or other metastases, suggesting clonal evolution.
Conclusions:
- The developed NGS assay is feasible for comprehensive genotypic profiling of melanoma.
- Identification of concurrent gene variants offers potential additional therapeutic targets.
- Detected genetic heterogeneity may explain mechanisms of secondary therapeutic resistance in melanoma.
