How long can someone live if they have melanoma?

Depends: That is a very open ended question. Early stage melanoma has a very good chance for cure whereas advanced melanoma is almost always fatal. Thus the importance of avoiding undue uv exposure and of getting good yearly skin exams, especially people with fair skin and history of sun exposure. The earlier it is found, the better your odds.

Depends on Stage: Survival from melanoma (or really any cancer) depends on the stage of the cancer, which in the case of melanoma is derived from the initial tumor thickness, whether there is ulceration, the extent of lymph node involvement (if any) and whether e melanoma has spread to distant, internal, organs.

Depends on the stage: Survival depends on the stage of disease and the overall health of the individual.