How long would someone have to live if their cancer is metastasis?

It varies : This is often a very difficult, if not impossible, question to answer for patients. Knowing someone's cancer type and stage and overall health, we can look at statistics of comparable patients and provide estimates of response to therapy, but this is, at best, an educated guess. Statistics are for populations, not for individuals--what does someone look like who has "70% survived" a cancer?

Usually not long: Although the variation is wide, for most solid tissue tumors such as breast, prostate, and colon cancers, after the cancer has metastasized the 5 year survival rate is low even with aggressive chemotherapy and other cancer treatments. Some cancers like metastatic testicular cancer have an excellent 5-year survival rate (80%). See: http://sgoti.Ws/zqpr2w.