Can doctors tell me what does untreated prostate cancer actually do to your body?

Highly variable.: The behavior of prostate cancer varies widely. Many men with low risk, low grade prostate cancer will die of other causes and the cancer that they harbor will have no impact on their lives. If the prostate cancer is aggressive, it can spread outside the prostate, invading nearby organs such as the bladder or rectum, then spread to the bones. Symptoms can range from minimal to severe.