Feb. 11, 2011 -- An experimental, noninvasive test that relies on a special adhesive tape to collect cells from suspicious skin lesions can accurately identify both early and advanced melanomas, researchers say.
The test identified localized and invasive melanomas 100% of the time, with a 12% rate of false-positives, in a study performed at 18 sites across the U.S.
Its incidence has doubled over the last two decades, and in the U.S., the increase has been especially dramatic among young women and older men.
According to the National Cancer Institute, invasive melanoma rates have increased by almost 4% annually among women aged 15 to 34 since 1995 and rates have increased by almost 9% a year since 2003 in men older than 65.
Melanomas are typically identified as a result of visual inspection of skin lesions by a dermatologist, followed by biopsy when the lesions are deemed suspicious.
This approach relies heavily on the clinical expertise of the dermatologist and pathologist, says dermatologist Mitchell Kline, MD, of the New York Presbyterian-Weill Cornell Medical School.
Some studies suggest that as many as 40 biopsies are performed for every melanoma detected, Kline says.
The experimental tape test is being developed by California-based biotech company DermTech International, which funded the research.
Using a patented technology known as Epidermal Genetic Information Retrieval, researchers were able to collect RNA from suspicious skin lesions before biopsies were performed using the special adhesive strip.
The RNA samples were then sent to the company’s lab for genetic analysis. Earlier research identified genes that are specific to melanomas, and the analysis included 17 of these.
Study researcher William Wachsman, MD, PhD, says the 17-gene biomarker can even differentiate between very early and invasive disease.
He is an associate professor of medicine at the University of California, San Diego School of Medicine and a staff physician at the VA San Diego Healthcare System. He also served on the scientific advisory board of DermTech.
More Tests Before Seeking FDA Approval
The study, published earlier this week in the British Journal of Dermatology, included 202 lesion samples that were taped over the course of a year.
Dermatologist James Zalla, MD, tells WebMD the test was 100% accurate at spotting melanomas identified at his Florence, Ky., practice during the study period. The genetic analysis even identified one very early malignancy that he and a pathologist had missed in their initial analysis of a lesion taken from a young man in his 20s.
Wachsman says DermTech researchers are working to bring the cost of the test down and more testing will be conducted before the company seeks FDA approval.
“If all goes well, we hope this test is in the hands of the melanoma community in about two years,” he says.
But it remains to be seen if dermatologists will embrace it.
Kline, who was not a study researcher, says the test might be especially attractive when patients want to avoid a scar or for lesions occurring on a part of the body where a biopsy would leave the patient in a lot of pain, such as the sole of the foot.