Since the demonstrated clinical success of BRAF/MEK inhibitors in patients with metastatic melanoma harboring BRAF mutations, attention has been focused on liquid biopsy to detect BRAF mutations in cell-free DNA (cfDNA) using droplet digital PCR (ddPCR) or next-generation sequencing methods. In this study, we investigated gene mutations in tumor DNA and cfDNA collected from 43 melanoma patients and evaluate their potential as biomarkers. ddPCR and CAncer Personalized Profiling by deep Sequencing (CAPP-Seq) techniques were performed to detect gene mutations in plasma cfDNA obtained from patients with metastatic melanoma. The sensitivity and specificity for BRAF mutation detection using ddPCR in cfDNA were 54.5 % and 100 %, respectively. Additionally, gene variants, including NRAS,TP53, GNAS, and MET, were detectable in the plasma cfDNA, and the results were partially consistent with the results of those identified in the tissues. Among the variants examined, copy numbers of MET mutations were consistent with the disease status in two melanoma patients treated with a BRAF/MEK inhibitor. In conclusion, liquid biopsy using CAPP-Seq and ddPCR has the potential to detect tumor presence and mutations, especially when tissue biopsies are unavailable. Additionally, MET mutations in cfDNA may be a potential biomarker in patients with metastatic melanoma.

ESDR486 - Liquid biopsy-based analysis using cell-free DNA from melanoma patients

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.