Stage 4 melanoma that has spread to internal organs is very difficult to cure, and the outlook is poor, according to American Cancer Society. However, some people do respond well to treatment and survive for years after diagnosis.
Treatment for stage 4 melanoma is dependent on whether the tumor can be surgically removed, how many tumors there are and where the tumor is located, states American Cancer Society. Tumors that cannot be removed are treated with chemotherapy, immunotherapy or targeted therapy. Stage 4 melanoma is difficult to treat with current available therapies, and patients may wish to take part in a clinical trial. Immunotherapy and chemotherapy only help a small percentage of people with advanced melanoma.