545 Long-term outcome of pigmented lesions clinically suspicious for melanoma previously tested with the Pigmented Lesion Assay (PLA): Results from the TRUST Study

Abstract

The assessment of pigmented lesions suspicious for melanoma remains a challenge. The non-invasive Pigmented Lesion Assay (PLA) guides biopsy decisions and detects melanoma at its earliest stages based on genomic atypia. The TRUST Study presented here is a long-term 12-24-month re-test follow-up study of lesions that initially tested negative for melanoma with the PLA. The study was designed to determine the proportion of true negative lesions among those that tested negative. Of the 1,781 lesions in the long-term follow-up screening cohort, there were no melanoma deaths or late-stage melanoma detected from these lesions. Ten lesions from the full cohort had received a melanoma diagnosis after initial testing, with four (0.3%) at Stage 0 (in situ) and six (0.5%) at Stage 1a. The negative predictive value (NPV) in a subset of 1,233 lesions with confirmed follow-up evaluations was 99.2% (CI95%= 98.5 - 99.6). Of the 302 lesions assessed by means of repeat testing with the PLA, none (0%) were found to have clinically obvious melanoma upon the subject’s return to the clinic, confirming the results of the initial chart review. Of these 302 lesions, 88.7% percent (268 lesions) were negative on repeat testing with the PLA and 34 (11.3%) were positive. All 34 lesions (100%) were surgically biopsied, with 3 (1%) diagnosed as Stage 0 (in situ), identified 13, 14 and 19 months after the initial PLA (NPV = 99.0% [CI95% = 97.1 - 99.8]). This long-term repeat-testing study confirmed the NPV of the PLA and found no adverse outcomes related to the test’s routine use.