Liquid biopsy as a potential tool for diagnosis and clinical monitoring of cutaneous and uveal melanoma

Melanoma is the most aggressive type of skin cancer, characterized by high metastatic potential and high mortality rates. Currently, diagnosis and mutational status assessment involves the excisional tissue biopsy followed by anatomopathological and immunohistochemical analyses. However, this technique is invasive and does not assess the molecular heterogeneity of the tumor. Also, it cannot be applied for the continuous monitoring of the disease. Gathering this information is essential for tumor staging, as well as for helping to select the most appropriate therapeutic approach for the patient. To overcome these limitations, liquid biopsy has arisen as an innovative diagnostic tool, which is a molecular determination technique for assessing tumor heterogeneity. Liquid biopsy is defined as the sampling of circulating biomarkers from tumor cells in various biological matrices, including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating tumor RNA, extracellular vesicles (EVs), and proteins. In this review, we will discuss the potential of liquid biopsy for the clinical assessment of cutaneous and uveal melanoma, evaluating advantages and some parameters, such as efficiency and specificity. To this end, a bibliographical survey was carried out in the main search databases for scientific articles in the health area, published between March 2019 and October 2024, using the keywords “melanoma”, “biomarker”, and “liquid biopsy”, and 56 articles were found. All these articles highlight the potential of liquid biopsy for personalized treatment of melanoma, early screening, diagnosis and prognosis, detection of relapses, monitoring of metastases, and selection of appropriated treatments. However, additional randomized controlled clinical trials comparing the use of liquid biopsy with the diagnostic gold standard are still needed to validate and evaluate the benefits of its use in clinical practice.