Circulating tumour DNA (ctDNA) as a liquid biopsy for melanoma

•ctDNA as a biomarker of disease status in advanced melanoma.•ctDNA as an indicator of response to treatment.•ctDNA for monitoring clonal evolution and emergence of resistance.•Epigenetic changes in melanoma ctDNA.•The challenges associated with clinical implementation of ctDNA for melanoma management.

Circulating tumour DNA (ctDNA) has emerged as a promising blood-based biomarker for monitoring disease status of patients with advanced cancers. In melanoma, ctDNA has been shown to have clinical value as an alternative tumour source for the detection clinically targetable mutations for the assessment of response to therapy. This review provides a critical summary of the evidence that gives credence to the utility of ctDNA as a biomarker for monitoring of disease status in advanced melanoma and the steps required for its implementation into clinical settings.