There’s no specific timeline that doctors can assign to any type of cancer. Some cancers, like breast and bowel tumors, start growing about 10 years before they’re diagnosed. Others can be a few decades old before they’re noticed. Additionally, there’s no way to determine how long cancer will last once it’s diagnosed. It all depends on the therapy, the overall health of the patient, and many other factors. However, if you remain in complete remission for five years, some doctors may say you’re cured. Keep in mind that cancer survival rates are different for everyone.