The prostate is found only in a man. It is part of the sex organs and is found or located just below the bladder. It is commonly described as walnut shaped and varies in size between a walnut and a small mandarin. It surrounds the urethra or tube that men urinate or pee through. As men age it tends to enlarge and can block off the gap through which urine flows. This gives rise to frequent passage of urine with poor flow. Difficulty peeing is usually not because of prostate cancer.
The prostate sits below the bladder and urine passes through the middle of it.
The prostate starts life in the embryo as separate organs or lobes around the urethra, which then fuse or join together. The outer portion called the peripheral zone is where cancers can later occur. This is the side next to the rectum, which is why doctors do rectal examinations, as cancers can sometimes be felt. The inner portion of the prostate is more likely to have benign growths in it, called BPH. It is the inner part which gets bigger as you age.
The prostate makes fluid which helps the sperm survive when trying to fertilise an egg. Once you have had children the prostate is not required. It's removal will make you infertile and mean that no fluid is ejaculated when you have an orgasm.
The prostate is an oval or semi-round structure, firm and divided into zones as below. As discussed above the peripheral zone is where cancers generally develop, while enlargement of the transition zone is not due to cancer.
Prostate cancers commonly occur in the peripheral zone, benign blockage in the transition zone
Symptoms of problems passing urine are usually not related to cancer. This is because problems passing urine are usually because the inner portion or part got bigger and squeezed the tube you pee through. This growth is almost always benign i.e. not cancer.
Prostate cancer usually grows on the outside of the prostate. Sometimes it is at the very front of the prostate. Both these places do not block the urine and so prostate cancer usually has no symptoms. To find prostate cancer at an early stage you need to have a rectal examination and a blood test called a PSA.
No, some prostate cancers do not make very much PSA but oddly enough can be felt on a rectal examination. This can because the prostate is small or the cancer is more aggressive. More aggressive prostate cancers do not always make PSA. You need both tests.