The prostate is a small gland located underneath the bladder in men. It is about the size of a walnut and fits around the tube (called the urethra) which carries urine out of the bladder. The prostate produces some of the fluid that mixes with sperm when a man ejaculates.
Prostate cancer is caused when cells in the prostate multiply and grow out of control to form a mass or tumour. It is a very variable disease. Some tumours remain small and grow so slowly that they cause no problems for the rest of a man’s life; others are aggressive, grow quickly and become life-threatening. Many of these aggressive cases will eventually spread to the bones, where they can cause severe pain.
Prostate cancer is now the most commonly diagnosed male cancer in many western countries. Currently there are 37,000 new cases a year in the UK; 218,000 in the USA; 25,000 in Canada and 17,000 new cases a year in Australia. The number of recorded cases has increased a lot in recent years. This is partly due to the increased use of the PSA test, which has resulted in more cases being detected, and partly due to the fact that men are living longer. Like most cancers, prostate cancer is more common in those over 60.
Main symptoms include:
However, all of these symptoms can also be caused by other conditions such as benign prostate enlargement.
There are no known causes for prostate cancer. However, between 5% and 10% of cases run in families, where the patient inherits a high risk of this type of cancer.
Prostate cancer is very rare in men under 50. The risk increases after the age of 50 with half of all cases occurring in men over 70. Men from families with a history of prostate cancer are at higher risk than normal. Race also has an effect: men of Afro-Caribbean descent are about twice as likely to get it whereas men of Asian descent have a lower risk of prostate cancer.
Some evidence suggests that a diet high in tomatoes, Vitamin E, cruciform vegetables (such as broccoli, cabbage, cauliflower and brussels sprouts) and selenium may reduce the risk of prostate cancer. However, other studies have failed to confirm these effects, so the findings of this prostate cancer research have not been confirmed.
If prostate cancer is diagnosed early, it can be treated very successfully. However, when the cancer is advanced, it becomes very difficult to cure.
If the cancer is diagnosed early (before it has spread outside the prostate gland), treatment provides a long-term cure for at least nine out of ten cases. However, if the cancer has spread outside the gland when diagnosed the prospects are worse. Even a small amount of spread reduces the chance of a cure quite a lot. More distant spread makes a cure very unlikely indeed. Treatment can give these patients extra years of life and stop the pain of the disease, but is only able to cure a minority of them. Overall, only about one in three of patients with spread outside the prostate survive for five or more years after diagnosis.
Sometimes prostate cancers are so slow growing that no treatment is needed. ‘Watchful waiting’ is used in these cases, with regular monitoring of the patient, by regular PSA tests, to find out if the cancer changes. However, when treatment is necessary, there are four main types used:
The treatments for prostate cancer carry a significant risk of side-effects, both long-term and short-term. All these treatments carry a high risk of infertility.
After a prostatectomy operation there is a high risk of impotence and a small risk of urinary incontinence.
Radiotherapy carries a similar risk of impotence but has a smaller risk of incontinence.
Brachytherapy appears to have a lower risk of impotence.
Almost all patients receiving hormone therapy experience impotence during the course of the treatment. Hot flushes, tiredness and weight gain are also common.