II. Indications
- Pigmented lesions with at least one atypical features (ABCDE) AND
- Adults with Fitzpatrick Skin Type 1-3 (white)
III. Contraindications
- Highly suspicious lesions (biopsy instead), Psoriasis, Eczema, Skin Ulcers, bleeding or scarring
- Also avoid for lesions on palms, soles, nails, mucous membranes, hairy areas
IV. Mechanism
- Adhesive sticker is applied to the entire surface of a suspicious pigmented skin lesion 5 to 16 mm
- Skin cells adhere to adhesive sticker, that is removed and submitted for analysis
- Dermtech PLA targets Melanoma genome markers in RNA (LINC00518, PRAME) with or without DNA (TERT)
- Results are back within 5 days of sample submission (Dermtech PLA)
- Biopsy is recommended when a positive marker is identified
V. Efficacy
- Limited by lower quality studies and False Negative Rate that may miss Melanoma
- Reduces number of biopsies needed to identify 1 Melanoma (from NNT 20, to NNT 2.7 to 5.1)
- Adhesive stickers contain RNA insuffiicient for testing in 15% of samples
- Test Sensitivity 73.7% (NPV 98.6%, LR- 0.3)
- Test Specificity 89% (PPV 25%, LR+ 7.1)
VI. References
- Espinosa (2024) AM Fam Physician 109(3): 277-8
- Thomsen (2023) Skin Res Technol 29(3):e13286 +PMID: 36973976 [PubMed]