Prostate cancer. Computer artwork of a cancerous tumour (centre left) in the prostate gland (red, centre). The urethra can be seen running down the centre of the prostate, from the bladder (top). Prostate cancer is one of the most common male cancers, usually affecting the elderly. The growth of a prostate tumour can obstruct the neck of the bladder, impairing urination. However, it is a slow-growing cancer. If diagnosed, treatment involves surgery to remove the prostate gland, or radiotherapy.