Prostate cancer

Prostate cancer is the uncontrolled growth of cells in the prostate, a gland in the male reproductive system just below the bladder. Early prostate cancer usually causes no symptoms. As the tumor grows, it can damage nearby organs causing erectile dysfunction, blood in the urine or semen, and trouble urinating. Some tumors eventually spread to other areas of the body, particularly the bones and lymph nodes. There, tumors cause severe bone pain, leg weakness or paralysis, and eventually death. Most cases of prostate cancer are detected by prostate cancer screening programs. These typically rely on regular blood tests for levels of prostate-specific antigen (PSA), which is elevated in those with prostate cancer or other conditions affecting the prostate. Screening can also involve a digital rectal exam to feel for prominent prostate tumors. A definitive diagnosis requires a biopsy of the prostate. A sample of the suspected tumor is examined by a pathologist under a microscope. If cancer is present, the pathologist assigns a Gleason score of 6 to 10, with higher scores representing a more dangerous tumor. Medical imaging is performed to look for cancer spread outside the prostate. Based on the Gleason score, PSA levels, and imaging results, a cancer case is assigned a stage. Higher stage signifies a more advanced, more dangerous disease. Most prostate tumors remain small and cause no health problems. These are managed with active surveillance, monitoring the tumor with regular tests to ensure it has not grown. Tumors more likely to be dangerous can be destroyed with radiation therapy or surgically removed by radical prostatectomy. Those whose cancer returns or has already spread beyond the prostate, are treated with hormone therapy that reduces levels of the male sex hormones that prostate cells need in order to survive. This halts tumor growth for a while, but eventually cancer cells grow resistant to this treatment. This most-advanced stage of the disease, called castration-resistant prostate cancer, is treated with continued hormone therapy alongside the chemotherapy drug docetaxel.