Melanoma is a cancer that begins in specific skin cells called melanocytes. Because most of these cells still make melanin, melanoma tumors are often brown or black, though this is not always the case. According to the American Cancer Society, melanoma most often starts on the chest or back in men and on the legs of women. Although melanoma much less common than basal cell and squamous cell skin cancers, it is far more dangerous and is likely to spread to other parts of the body if it is not caught early.
It is estimated that there were approximately 76,100 new cases of melanoma of the skin and an estimated 9,700 people died of this disease in the United States in 2014. Five-year survival for Stage 3 melanoma (lymphatic involvement) ranges from about 40% to 75% and for Stage 4 (metastatic) is approximately 15% to 20% in the United States. Patients with Stage 4 melanoma suffer an especially poor prognosis with a median survival of six to 10 months.