Noninvasive Diagnosis of Melanoma Uses Adhesive Tape and Genetic Testing
Early detection and treatment of melanoma is important for optimal clinical outcome. Excisional biopsy of pigmented lesions deemed suspicious for the disease is the current method for diagnosis. The vast majority of such lesions biopsied are benign.
A noninvasive genomic test for melanoma has been developed by DermTech International which relies on a patented technology known as Epidermal Genetic Information Retrieval (EGIR) allows the collection of RNA from suspicious skin lesions before biopsies were performed using a special adhesive strip.
William Wachsman, MD, PhD and colleagues conducted a study to determine the accuracy of the adhesive tape using the EGIR technology. The results are reported in the British Journal of Dermatology included 202 lesion samples that were taped over the course of a year.
The researchers harvested skin overlying pigmented lesions clinically suspicious for melanoma using EGIR. RNA isolated from the tapes was amplified and gene expression profiled. All lesions were removed for histopathologic evaluation.
Earlier research identified 312 genes that are specific to melanomas, and the analysis included subset of 17 of these.
Upon testing with an independent dataset, this classifier discerns in situ and invasive melanomas from nevi with 100% sensitivity and 88% specificity, with an area under the curve for the receiver operating characteristic of >0.955.
The test has been patented, but has not sought FDA approval so it will be a few years before the average doctor has access to this noninvasive technique for diagnosing melanoma.
Melanoma remains the most serious form of skin cancer. It is almost always curable in its early stages. If melanoma is not caught early, it can advance and spread to other parts of the body. It then becomes hard to treat and can be fatal.
Melanoma accounts for less than 5% of all skin cancers, but accounts for the approximately 74% of all deaths from skin cancers.
Everyone is at some risk for melanoma, but increased risk depends on several factors: sun exposure, number of moles on the skin, skin type and family history (genetics).
For many years, the early warning signs of melanoma have been identified by the acronym "ABCDE" (A stands for Asymmetry, B stands for Border, C for Color, D for Diameter and E for Evolving or changing was recently added.).
A new concept of the “ugly duckling” has been added to pick up the melanomas that don’t fit the ABCDE rule. This new method of sight detection for skin lesions is based on the concept that these melanomas look different -- ie, "the ugly duckling" -- compared to surrounding moles.
For early detection of melanoma, look for lesions that manifest the ABCDE's AND for lesions that look different compared to surrounding moles.
If you are in any of these risk groups, you can protect yourself and your children by practicing safe sun habits, remembering to examine yourself regularly, watching for the warning signs and getting yearly exams by a dermatologist or other physician experienced in skin care.
Non-Invasive Genomic Detection of Melanoma; Wachsman W, Morhenn V, Palmer T, Walls L, Hata T, Zalla J, Scheinberg R, Sofen H, Mraz S, Gross K, Rabinovitz H, Polsky D, Chang S; British Journal of Dermatology; DOI: 10.1111/j.1365-2133.2011.10239.x