|Metastasis is the movement or spreading of cancer cells from one organ or tissue to another. Cancer cells usually spread through the blood or the lymph system. If a cancer spreads, it is said to have "metastasized." The lungs are the second most frequent site of metastases from extra thoracic malignancies, while 20% of metastatic diseases is isolated to the lungs. At the same time, they are the second most common site for metastatic malignant melanoma, with a one-year survival rate of 53%. Metastasectomy remains the primary treatment for Melanoma Lung Metastases (MLM) with = 2 nodules and chemotherapy is principally used in those with multiple metastases. Several chemotherapeutic drugs are available, including dacarbazine, cisplatin, carmusine (also in combination with various immunotherapies), BOLD-regimen+G-CSF, ipilimumab, nivolumab, vemurafenib and the association between dabrafenib and trametenib.
Regarding the first anatomical site, it is known that many of the preferences observed for the spread of specific cancers to specific metastatic locations can be explained by the direction of blood flow. In this regard, organs in close proximity are likely to be the main sites of metastases for a particular primary tumor. While, generally, malignant melanoma is usually considered as different from other solid tumors, because it is a cutaneous malignancy with straightforward lymphatic flow, which can be mapped. However about one-third of the locations of frequent metastases is puzzling about this observation. In our sample, although 68% of patients showed an axial primary tumor, TMLM and OS were both worse for those arisen in the peripheral sites. At the Cox proportional hazards-regression, anatomical site remained the main predictor.