Gene expression analysis effective in melanoma detection in skin of color
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Key takeaways:
- Noninvasive gene expression testing by DermTech detects melanoma equally in all Fitzpatrick skin types.
- The test uses RNA extracted from skin cells collected with adhesive patches.
In patients with Fitzpatrick skin types IV through VI, gene expression analysis can help rule out melanoma, according to a poster presented at the Winter Clinical Dermatology Conference.
A previous study evaluated the use of noninvasive gene expression programming (GEP) to rule out melanoma with a negative predictive value in people with mostly skin types I, II and III. Researchers aimed to further study this method in patients with skin of color.
“The more common melanoma subtypes are less common among individuals with Fitzpatrick skin types IV to VI than those with types I to III. As a result, differentiating melanoma from benign lesions in these skin types can be challenging,” Neal Bhatia, MD, director of clinical dermatology at Therapeutics Clinical Research in San Diego and one of the study’s authors, told Healio. “Numerous studies suggest that melanomas in skin types IV to VI are more likely to present at an advanced stage and result in higher mortality. Noninvasive methods may be especially helpful in the assessment of pigmented skin lesions in these patients.”
Bhatia and colleagues compared 2-GEP assay test findings from 4,152 patients with Fitzpatrick skin types I to III with 130 patients with skin types IV to VI. Skin cells were collected with noninvasive adhesive patches and RNA was extracted from these and analyzed to detect PRAME and LINC00518 RNA expression.
Those with negative lesions were followed by clinical surveillance.
There was no significant difference in the negative predictive values between the two groups. The negative predictive value of the skin types I to III group was 0.9989, compared with 1 in the skin types IV to VI group. Sensitivity and specificity were also both 90% or greater in each group.
“Clinicians can be just as confident that a pigmented lesion with a negative test result is not melanoma in a patient with Fitzpatrick skin type of IV, V or VI as they can in a patient with a Fitzpatrick skin type of I to III, but clinical suspicion should still be followed,” Bhatia said.