Liquid Biopsy for Uveal Melanoma

Despite improvements in the treatment of uveal melanoma (UM), prevention and therapy of systemic metastasis remain unsolved. Current prognostic indicators, either alone or in combination, may predict the pattern of progression and outcome. However, metastasis-related death has been recorded in patients initially diagnosed with early-stage cancer and in other patients many years after initial tumor removal. The mechanisms leading to the extravasation, dissemination, and colonization of organs by UM cells are still unknown but crucial for future therapies. The detection and characterization of circulating melanoma cells (CMCs) can aid in the diagnosis, prognosis, and disease monitoring of UM patients. Furthermore, CMCs provide additional information that cannot be acquired by studying the primary tumor alone. “Liquid biopsy” therefore has substantial potential to serve as an additional tool in the care of UM patients. CMCs can be characterized for the presence of key prognostic factors, such as monosomy-3, and used as a prognostic tool particularly in patients undergoing eye-preserving therapy and where no tumor biopsy is collected. The isolated cells can be further studied in vitro to better understand the mechanisms of dissemination and proliferation in the liver. The detection of circulating tumor cells has reached a prominent role in the treatment monitoring of various cancers. Analysis of the CMC in UM patients may assume a similar, leading role in the near future for the early identification of patients at high risk of metastatic disease.