2-GEP test rules out melanoma in real-world study
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Key takeaways:
- DermTech’s GEP-2 assay test is a noninvasive way to detect melanoma in lesions.
- This study found the test had a negative predictive value of more than 99%.
The noninvasive 2-gene expression profiling assay test has the ability to rule out melanoma with a negative predictive value over 99%, according to a real-world study presented at the Winter Clinical Conference.
“The 2-[gene expression profiling (GEP)] assay (DermTech) uses RT-qPCR to detect the gene expression of PRAME and LINC00518 RNA, two biomarkers that are common in melanomas but uncommon in their benign simulators, extracted from skin cells collected with noninvasive adhesive patches,” Laura Korb Ferris, MD, PhD, professor of dermatology at the University of Pittsburgh Clinical and Translational Science Institute and director of clinical trials at UPMC department of dermatology, told Healio.
The multicenter Trust 2 registry study included lesions from 19,653 patients, which were tested using the 2-GEP test.
Follow-up visits evaluated the lesions for changes. In 5,096 cases, pathology diagnosis for lesions were biopsied.
The Clopper-Pearson Exact Binomial Test was used to calculate the 95% confidence intervals for negative predictive value (NPV) and positive predictive value (PPV), whereas the Farrington-Manning method was used to calculate the 95% confidence intervals for the difference in NPV and PPV.
The NPV was calculated at 99.7% with a sensitivity of 95.8% and a specificity of 69.4%, as well as a PPV of 13.4%.
“The sensitivity of the test in this very large-scale U.S. study was even higher than in the validation study. The specificity observed in this real-world study was nearly identical to that in the original validation when compared to consensus (triple read) pathology,” Ferris told Healio. “The test has repeatedly demonstrated high performance metrics in now four published studies, all of which also most importantly confirm the NPV of greater than 99%. That is the true clinical utility that the 2-GEP test provides clinicians.”
These results further validate previous trials and can improve the management of pigmented lesions beyond visual inspection, Ferris said.