II. Indications

  1. Pigmented lesions with at least one atypical features (ABCDE) AND
  2. Adults with Fitzpatrick Skin Type 1-3 (white)

III. Contraindications

  1. Highly suspicious lesions (biopsy instead), Psoriasis, Eczema, Skin Ulcers, bleeding or scarring
  2. Also avoid for lesions on palms, soles, nails, mucous membranes, hairy areas

IV. Mechanism

  1. Adhesive sticker is applied to the entire surface of a suspicious pigmented skin lesion 5 to 16 mm
  2. Skin cells adhere to adhesive sticker, that is removed and submitted for analysis
  3. Dermtech PLA targets Melanoma genome markers in RNA (LINC00518, PRAME) with or without DNA (TERT)
    1. Results are back within 5 days of sample submission (Dermtech PLA)
    2. Biopsy is recommended when a positive marker is identified

V. Efficacy

  1. Limited by lower quality studies and False Negative Rate that may miss Melanoma
  2. Reduces number of biopsies needed to identify 1 Melanoma (from NNT 20, to NNT 2.7 to 5.1)
  3. Adhesive stickers contain RNA insuffiicient for testing in 15% of samples
  4. Test Sensitivity 73.7% (NPV 98.6%, LR- 0.3)
  5. Test Specificity 89% (PPV 25%, LR+ 7.1)

VI. References

  1. Espinosa (2024) AM Fam Physician 109(3): 277-8
  2. Thomsen (2023) Skin Res Technol 29(3):e13286 +PMID: 36973976 [PubMed]

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