Pigmented Lesion Assay
The PLA provides physicians with a non-invasive option to identify clinically atypical pigmented lesions (or moles) at high risk for melanoma using an adhesive patch rather than a scalpel.
“The noninvasive pigmented lesion assay enables dermatologists to biopsy fewer benign pigmented skin lesions while missing fewer melanomas.
This result may increase the number of early melanomas biopsied and reduce the number of benign lesions biopsied, thereby improving patient outcomes and reducing healthcare cost.” — JAMA 2017
DermTech’s PLA can distinguish melanoma from benign pigmented skin lesions such as nevi or moles with a negative predictive value (NPV) of over 99%, sensitivity of 91%, and specificity of 69%, without the need for a surgical biopsy. The PLA uses stratum corneum tissue collected with adhesive patches included in our Adhesive Skin Collection Kit. The PLA has advantages in patient comfort and convenience as well as additional utility in patients who have multiple lesions, especially in cosmetically sensitive areas, are anti-coagulated, at increased risk for infection or scarring, or who are at risk for wound healing complications. Evidence is also increasing that the detected gene expression changes precede morphologic changes. (JAMA 2017)
See Your Diagnosis Differently with Non-Invasive Gene Expression
DermTech has identified a specific gene expression ‘signature’ test that is highly correlated with melanoma.2, 3 The PLA detects the expression of two specific genes, LINC00518 and PRAME. These two genes belong to separate classes of molecules that are known to have roles in oncogenesis, and both are elevated in melanoma. Gene expression results are summarized in a molecular pathology report.
PLA positive lesions are generally surgically biopsied to establish the diagnosis.
PLA negative lesions are generally monitored.
2-gene (LINC and PRAME) positive samples have a 93% correlation to melanoma by histopathology. PRAME only positive samples have a 50% correlation to melanoma by histopathology. LINC only positive samples have a 7% correlation to melanoma by histopathology.
When Should I Test?
The PLA test is intended for use on pigmented skin lesions, which are clinically suspicious for melanoma. These lesions may meet one or more ABCDE criteria.
PLA uses include:
- Lesions being followed for change
- Lesions in cosmetically sensitive areas
- Lesions on patients with potential contraindications to surgical biopsy including patients that are anti- coagulated, those at risk for infection, and those at risk for poor wound healing or elevated abnormal scarring
What is the adhesive skin collection kit?
The unique properties of the adhesive patches allows for the collection of skin samples with minimal patient discomfort and recovery time, while maximizing the collection of tissue for our PLA. A single kit contains all of the necessary components to complete the non-invasive biopsy:
- Adhesive patches
- Instructions for use
- Marking pen for outlining the lesion
- Pre-paid FedEx shipping envelope
- Laboratory requisition form
- 70% alcohol prep pad
- Gauze pad
At DermTech, We Love Making a Difference in Patient Care
“Recently, I had a young female patient with a mildly suspicious lesion on the back of her neck. Given the age of the patient, I am not sure I would have done an invasive biopsy on this lesion. Since I have the non-invasive PLA test in my office, I chose to do that first. The test came back positive for both LINC and PRAME and substantiated the need for a surgical biopsy. The histopathology showed a 1.1mm SS MM. You all may have saved her! The lesion didn’t look that bad, so I may have just photographed it and regularly monitored it. Having the PLA gave me an additional option to obtain objective information to guide my clinical treatment decision.
Wanting further information, I requested DermTech’s Nevome DNA reflex test be performed. The Nevome test detected DNA hot spot driver mutations TERT promoter and BRAF. The additional information provided by Nevome guided my follow-up protocol with this patient to bring her in for more frequent skin checks as well as to perform skin checks on her family members.”
Dr. Brook Brouha, M.D., Ph.D.
Board Certified Dermatologist and Dermatopathologist