A new test with adhesive tape could be effective in detecting melanomas in suspicious lesions on the skin.

This noninvasive experimental test relies on the adhesiveness of specialized tape to collect cells from skin lesions in order to diagnose skin cancer.

The adhesive tape, a patch about the size of a nickel, is rubbed directly over the lesion to collect RNA, which is analyzed for genes that are specific to melanoma, according to clinical medicine professor William Wachsman.

Melanomas are the leading cause of death from skin cancer — which is the most common form of cancer in the U.S.

Normally, dermatologists identify melanomas by first visually examining the region, then performing a biopsy if the region seems suspicious.

“We’re trying to provide an additional tool to the dermatologist that would enable them to make a better decision on whether to biopsy a lesion, and if they did biopsy it, they would be better off doing the appropriate excision,” Wachsman said.

More invasive biopsies have traditionally been performed on lesions as the main way of detecting melanomas. Biopsies of lesions remove parts of tissue in that region, leaving visible scars.

The vast majority of the suspicious lesions dermatologists examine  — which are darkly pigmented spots that resemble moles or birthmarks — do not turn out to be melanomas, according to Wachsman.

“They’ll often do something that is called shave or scoop biopsies,” Wachsman said. “On occasion, you can actually cut through the melanoma, especially if it’s invasive, and then you can’t even determine a stage of the disease.”

In addition, biopsies have a hit rate of 3.5 percent in effectively determining melanomas.

“Now, as opposed to a hit rate of 3.5 percent, they [the adhesive tape tests] have a hit rate of 88 percent,” Wachsman said.

By using RNA to detect melanomas, specific genes can be identified that lead to melanomas.

“We identified a grouping of 17 genes that formed the predictor [for melanoma],” Wachsman said. “It is essentially a multi-gene biomarker.”

The adhesive tape method can also differentiate between different stages of melanoma.

“It picks up both early forms of disease: the [inciting] stage of disease as well as [the] invasive stage of disease,” Wachsman said. “It also picks up the different subtypes of melanoma.”

Examining RNA from cells in the lesioned area can determine which genes coding for melanomas are activated.

“It’s not felt that melanoma actually exists in the stratum cornea, the topmost layer of the skin,” Wachsman said. “It’s actually below the surface. We were asking the question, ‘Can we possibly see a signal in the stratum cornea?’ What we’re surprised by is that we cannot see a signal, but it appears that there are genes that are known to be associated with melanoma in the stratum cornea.”

The adhesive tape method was developed by the La Jolla-based biotech company DermTech International, at which Wachsman serves as an advisor.

The adhesive tape test will undergo further testing before DermTech seeks approval from the Food and Drug Administration.