Liver metastasis in uveal melanoma-treatment options and clinical outcome

Uveal melanoma (UM) is the most prevalent primary intraocular malignancy in adults with a stable incidence rate between five and seven cases per million in Europe and the United States. Although UM and melanoma from other sites have the same origin, UM has different epidemiological, biological, pathological and clinical features including characteristic metastatic hepatotropism. Despite improvements in the treatment of primary tumours, approximately 50% of patients with UM will develop metastases. In 90% of cases the liver is the first site of metastasis, however the mechanisms underlying this hepatic tropism have not been elucidated. Metastatic disease is associated with a very poor prognosis with a median overall survival of 6 to 12 months. Currently, there is no standard systemic treatment available for metastatic UM and once liver metastases have developed, prognosis is relatively poor. In order to prolong survival, close follow-up in all patients with UM is recommended for early detection and treatment. The treatment of metastatic UM includes systemic chemotherapy, immunotherapy and molecular targeted therapy. Liver-directed therapies, such as resection, radioembolization, chemoembolization, immunoembolization, isolated and percutaneous liver perfusion as well as thermal ablation represent available treatment options. However, to date a consensus regarding the optimal method of treatment is still lacking and the importance of setting guidelines in the treatment and management of metastatic UM is becoming a priority. Improvement in knowledge and a better insight into tumour biology, immunology and metastatic mechanism may improve current treatment methods and lead to the development of new strategies paving the way for a personalized approach.