New Publication Supports Diagnostic Value of DermTech's PLA

Evaluation of genomic atypia with DermTech’s Pigmented Lesion Assay (PLA) increases both the real-world negative predictive value (NPV) and positive predictive value (PPV) of the melanoma diagnostic pathway and reduces biopsy burden, relative to the current visual assessment and histopathology pathway, new data show. The research appears in SKIN: The Journal of Cutaneous Medicine.

Results of the TRUST study indicate that the non-invasive detection of genomic atypia by the PLA can complement visual assessment of pigmented lesions and enhance the early detection of melanoma, enabling clinicians to triage suspicious lesions more effectively to determine which lesions are high risk and should be biopsied versus safely managing benign lesions via clinical surveillance, DermTech reports.

The TRUST study was conducted in the US using a cohort of 2,575 PLA-tested lesions for evidence of melanoma detected during a protracted follow-up period of up to 36 months and by re-testing a subset of 302 PLA-negative lesions up to 24 months after the initial PLA test. Results demonstrate that in this real-world intended use population, the PLA has an NPV of greater than 99%, confirming the high NPV established in previous clinical studies.

Real-world PPV of 18.7% was determined by identifying melanoma diagnoses among PLA-positive lesions within a US-based registry of 3,418 PLA-tested cases. The PLA’s detection of genomic atypia enriched the pool of biopsied lesions nearly five-fold for those most likely to be diagnosed as high-risk or severely atypical and malignant.

Of the 5,993 lesions tested with the PLA (TRUST Study and registry cases), the vast majority of PLA tests were negative and not subjected to surgical biopsy.

“Many tests require a compromise with respect to NPV and PPV in which optimizing one comes at the expense of the other. Maximum NPV is priority for a test designed to safely rule out melanoma, yet this study confirms that the PLA’s high NPV is balanced by a PPV that offers a significant improvement over the current care pathway,” says Dr. Maral Kibrian Skelsey, lead author and Clinical Associate Professor of Dermatology at Georgetown University.

“The TRUST Study illustrates that the PLA can detect melanoma at the earliest stages when it is curable. This long-term follow-up data of PLA-negative tests also provides clinicians confidence in use of this precision genomic technology to effectively rule out lesions not harboring melanoma,” says Dr. Gary Peck, co-author and melanoma expert at the Dermatologic Surgery Center of Washington.