MyPath^® Melanoma
Clinical Evidence

MyPath Melanoma Development & Validation

Using qRT-PCR technology, the test objectively distinguishes melanoma from benign nevi with greater than 90% accuracy in three independent clinical validations. In the initial discovery phase of test development, candidate genes were selected based upon published data demonstrating their differential expression in melanoma compared with benign nevi or their increased expression in aggressive tumors.

This panel was refined to a set of the 40 genes that most effectively differentiated benign and malignant melanocytic lesions, and these genes were then further assessed in a training cohort of archival formalin-fixed paraffin-embedded melanocytic lesions (n=464).

Statistical modeling identified a subset of 14 genes grouped into three distinct gene components which provided the greatest sensitivity and specificity. These 14 signature genes are involved in cell differentiation and cellular immune signaling.

Expression of the signature genes is normalized to that of 9 reference genes prior to the application of a weighted algorithm that combines the measurements of all signature genes and generates a single numerical score.

MyPath Melanoma Gene Component Information

The first component is 2 measurements of the gene PRAME, which stands for preferentially expressed antigen in melanoma. PRAME encodes a cancer-testis protein that is aberrantly expressed in melanoma. It appears to contribute to tumorigenesis by functioning as a dominant repressor of retinoic acid receptor signaling and/or down-regulation of TRAIL expression.

The second component contains 5 genes from the S100A family: S100A7, S100A8, S100A9, S100A12, and PI3. The products of these genes are involved in multiple cellular processes. S100A9 is a calcium binding protein often found in combination with S100A8 as part of an immunogenic protein heterodimer. Increased S100A8 and S100A9 levels are detected in many malignant neoplasms, both within tumor cells and within infiltrating immune cells.

The third component contains 8 genes involved in tumor immune response signaling: CCL5, CD38, CXCL10, CXCL9, IRF1, LCP2, PTPRC, and SELL. Many of these genes produce chemokines or chemokine receptors that regulate leukocyte trafficking. Chemokines can suppress or promote the growth of a neoplasm by acting on cells of the tumor microenvironment, including leukocytes, endothelial cells, and fibroblasts, but they may also affect tumor cells themselves by regulating migration, invasion, proliferation, and resistance to chemotherapy.

The fourth component is a group of 9 housekeeping genes whose measurement allows normalization of the RNA expression for analysis.

Clinical Validation of MyPath Melanoma

The test objectively distinguishes melanoma from benign nevi with greater than 90% accuracy in 3 independent clinical validations.

Validation Study 1:

Clarke L, Flake D, Busam K, et al. An independent validation of a gene expression signature to differentiate malignant melanoma from benign melanocytic nevi. Cancer 2016;123:617-28.

Retrospective cohort (n=437) representing broad range of clinical and histopathologic subtypes (entirely separate from training cohort)
Reference standard: Independent concordant diagnosis by 2 expert dermatopathologists
Sensitivity = 90%; Specificity = 91%

Diagnostic Score

Validation Study 2:

Clarke L, Mabey B, Flake D, et al. Clinical validity of a gene expression signature in diagnostically uncertain neoplasms. Per Med 2020;17:361-71.

Prospective cohort (n=1,172) of cases submitted for testing in the clinical setting
Reference standard: Independent concordant diagnosis by 3 expert dermatopathologists
Diagnostic concordance among all 3 in 736 cases
Sensitivity = 92%; Specificity = 93%
Included ambiguous / diagnostically equivocal cases; expert panelists documented uncertainty in >20% of the 736 cases (e.g., “indeterminate case,” “borderline tumor,” “requires ancillary studies,” “differential diagnosis includes nevus and melanoma,” “re-excise to exclude melanoma,” etc.)

Diagnostic Score

Validation Study 3:

Ko J, Matharoo-Ball B, Billings S, et al. Diagnostic distinction of malignant melanoma and benign nevi by a gene expression signature and correlation to clinical outcomes. Cancer Epidemiol Biomarkers Prev 2017;26:1107-13.

Retrospective cohort (n=182) with clinical outcomes
99 melanomas that developed documented distant metastasis after initial biopsy
83 nevi with median event-free follow-up > 6 years
Reference standard: Patient outcomes (distant metastasis or ≥ 5-year event-free follow-up)
Sensitivity = 94%; Specificity = 96%

Diagnostic Score

Clinical Utility Studies

The clinical utility of the MyPath® Melanoma score has been evaluated in two separate studies to best represent multiple aspects of the diagnostic and treatment paradigms.

These studies with experienced dermatopathologists demonstrate that use of the test increases the number of definitive diagnoses, decreases classification of lesions as ‘indeterminate’, and produces substantial changes in patient treatment.

Clinical Utility Study 1:

Cockerell C, Tschen J, Evans B, et al. The influence of a gene expression signature on the diagnosis and recommended treatment of melanocytic tumors by dermatopathologists. Medicine 2016;40:e4487.

Prospective cohort (n=218) of cases submitted for testing in the clinical setting
56.6% increase in definitive diagnoses in ambiguous cases

Pre-Test Diagnosis

Benign

Indeterminate

Malignant

Post-Test Diagnosis

Benign

Indeterminate

Malignant

Clinical Utility Study 2:

Cockerell C, Tschen J, Billings S, et al. The influence of a gene-expression signature on the treatment of diagnostically challenging melanocytic lesions. Per Med 2017;14:123-30.

Prospective cohort (n=77) of ambiguous cases (“indeterminate” per dermatopathologist)
Compared referring dermatopathologist pre-test management recommendation with actual patient treatment received by patient post-test at 6-12 months follow-up
71.4% change from pre-test treatment recommendation to actual treatment performed

Pre-Test Treatment Recommendation

Re-Excision

LFU

No Re-Excision

Post-Test Treatment Recommendation

Re-Excision

LFU

No Re-Excision

MyPath Melanoma has demonstrated reproducible results across 10 publications including validation to dermatopathology experts' diagnoses and outcomes.

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MyPath^® Melanoma
Clinical Evidence

MyPath Melanoma Development & Validation

MyPath Melanoma Gene Component Information