By Mayo Clinic News Network

Stage 4 prostate cancer is cancer that begins in the prostate and grows to involve nearby organs or spreads to other areas of the body.

Stage 4 prostate cancer is an uncommon diagnosis. Most cases of prostate cancer are diagnosed at an earlier stage, when the cancer is confined to the prostate.

Treatments may slow or shrink an advanced prostate cancer, but for most men, stage 4 prostate cancer isn't curable. Still, treatments can extend your life and reduce the signs and symptoms of cancer.

Source: http://www.mayoclinic.org/diseases-conditions/stage-4-prostate-cancer/basics/definition/con-20094020/