The average life expectancy of a person whose melanoma has spread outside the local area or into the lymph nodes is 7.5 months, according to the Cancer Center at the University of New Mexico. Less than 10 percent of these patients survived beyond five years.
A study published in the Journal of the American Medical Association for Dermatology notes that melanomas are an aggressive form of skin cancer with a high risk of spreading to other parts of the body. Some cases of melanoma are known to experience a partial and spontaneous remission without treatment. However, a complete remission without treatment is rare.