Extracellular vesicles as a liquid biopsy for melanoma: Are we there yet?

Melanoma is the most aggressive form of skin cancer owing to its high propensity to metastasise in distant organs and develop resistance to treatment. The scarce treatment options available for melanoma underscore the need for biomarkers to guide treatment decisions. In this context, an attractive alternative to overcome the limitations of repeated tissue sampling is the analysis of peripheral blood samples, referred to as 'liquid biopsy'. In particular, the analysis of extracellular vesicles (EVs) has emerged as a promising candidate due to their role in orchestrating cancer dissemination, immune modulation, and drug resistance. As we gain insights into the role of EVs in cancer and melanoma their potential for clinical use is becoming apparent. Herein, we critically summarise the current evidence supporting EVs as biomarkers for melanoma diagnosis, prognostication, therapy response prediction, and drug resistance. EVs are proposed as a candidate biomarker for predicting therapeutic response to immune checkpoint inhibition. However, to realise the potential of EV analysis for clinical decision-making strong clinical validation is required, underscoring the need for further research in this area.