Prostate cancer. Coloured axial magnetic resonance imaging (MRI) scan of the lower abdomen of a 74- year-old man who has an adenocarcinoma of the prostate gland. The front of the body is at top in this view from below. The prostate gland (orange, centre) has been highlighted by the injection of a gadolinium contrast medium. The bladder (pink), partially seen above the enlarged prostate gland, is being compressed by the cancer, affecting urination. The circular areas at left and right are the tops of the thigh bones. The causes of prostate cancer are not known, but it is most prevalent in men over 50 years of age. Treatment is with hormone therapy, chemotherapy, or surgery to remove the prostate gland. This advanced cancer has a Gleason score of 9, and the patient has a PSA reading of 13.