What can i do if my grandfather was found today to have melanoma skin cancer. how long could he possibly live?

Melanoma: Melanoma prognosis depends on lymph node spread. The possibility of lymph node spread is directly dependent on depth of the melanoma (breslow depth). Staging uses the depth and lymph node involvement.

Melanoma : Melanoma survival rates are largely determined by the depth of the melanoma. A deeper melanoma is more likely to spread or metastasize. A more superficial lesion is not as likely to metastasize