People worry about melanoma. They closely track their moles, conducting ad hoc time studies with their iPhone cameras and circling questionable ones with Sharpies for their dermatologists to review. They want to catch any disease on the whisper. The five-year survival rate for stage 0, 1 and 2 melanoma is 98.4%. Stage 3 is 63.6%. Stage 4 is 22.5%.
Dermatologists, pathologists and internists feel that anxiety as well: It’s a diagnosis they never want to miss. That’s the driving force behind DermTech, which has developed a band aid-like device, called Smart Sticker, that captures mole tissue for molecular testing. According to the company, the test can confirm a mole is benign with 99% accuracy.
“The idea is that it can rule out melanoma without the need for a biopsy in every case,” said Loren Clarke, M.D., a pathologist and DermTech’s chief medical officer, in a recent interview. “Instead of needing to biopsy each and every one of these vaguely suspicious lesions, clinicians can use Smart Stickers to collect cells noninvasively from the outermost layer of skin.”
From there, the sample is sent to DermTech’s lab, which analyses it for two or three molecular biomarkers. Finding those markers doesn’t confirm it’s melanoma; however, doctors and patients may want to pursue a biopsy.
Coloring in the Gray Areas
DermTech believes the Smart Sticker could take some of the guesswork out of melanoma diagnoses, particularly at its earliest, most curable, stages.
“The problem is that differentiating very early stage melanoma from a benign mole is still extremely difficult, even for experienced dermatologists,” said Clarke. “In their early stages, melanomas can look just like a benign mole. Almost indistinguishable.”
The watchword is caution. If a dermatologist sees a suspicious mole, they may cut out a sample and send it to pathology. However, the vast majority of biopsied moles come back benign. Clinicians know these questionable moles are often over-biopsied, but cannot afford to be wrong. Even under a pathologist’s microscope, it can be difficult to make firm conclusions.
“For the same reason the dermatologist ends up biopsying a lesion, pathologists feel compelled to, if they can’t rule out melanoma definitively, recommend the dermatologist go back and do a re-excision, where they remove the entire biopsy site, along with, in most cases, a margin of normal skin around it to make sure it’s entirely eradicated.”
Once DermTech’s lab receives a sample, it analyzes two, or sometimes three, biomarkers (using RT qPCR). One test assesses LINC00518 and PRAME, RNA molecules commonly found in melanoma. An optional second test looks for TERT, which helps cancer cells survive.
The Smart Patch is covered by Medicare and some, but not all, private insurers. Clarke believes commercial payers will continue to adopt the test – it’s in their best interest.
“When you factor in the number of biopsies that go to a pathologist and, because they can’t rule out melanoma definitively, they say: you should probably do the complete excision. When you factor in that uncertainty, it’s pretty clear there are cost advantages to this,” said Clarke. “So, payers are definitely interested. Even the ones that are still hesitant to jump on board see the benefit and the value.”
