Patients with unresectable stage III or stage IV melanoma will be enrolled prospectively for 1 year with a 3 years follow-up (a total of 1000 patients will be enrolled) from 26 French centers A database of clinical monitoring of metastatic patients will be established and associated with a virtual tumor bank. This national database will be issued from the use of biological, clinical and imaging databases already available in the centers and optimized for this project; this database will also results from the interaction with the French national cancer institute (INCa) genotyping platform.