Prostate cancer generally affects men over 50 and is rare in younger men. It’s the most common type of cancer in men. It differs from most other cancers in the body, in that small areas of cancer within the prostate are very common and may stay dormant (inactive) for many years. It’s thought that about half (50%) of all men over 50 may have cancer cells in their prostate, and 8 out of 10 (80%) men over 80 have a small area of prostate cancer. Most of these cancers grow very slowly and so, particularly in elderly men, are unlikely to cause any problems. In a small proportion of men, prostate cancer can grow more quickly and in some cases may spread to other parts of the body, particularly the bones.
Early (localized) prostate cancer
Early cancer of the prostate gland (early prostate cancer) is when the cancer is only in the prostate and has not spread into the surrounding tissues or to other parts of the body. It is also called localized prostate cancer.
Locally advanced prostate cancer
Locally advanced prostate cancer is cancer that has spread into the tissues around the prostate gland. Cancer that has spread to other parts of the body is called metastatic prostate cancer.
Advanced (metastatic) prostate cancer
Advanced or metastatic cancer of the prostate gland is when the cancer has spread beyond the prostate gland to other parts of the body. Prostate cancer is usually diagnosed in the early stages before it starts to spread outside the prostate gland. But in some men, prostate cancer will be advanced when it is first diagnosed. Advanced prostate cancer can also occur in men who have previously been treated for early or locally advanced prostate cancer but their cancer has come back (relapsed or recurred). You can find out more about thestages of prostate cancer. Prostate cancer cells can sometimes spread beyond the prostate gland. The cancer cells may travel around the body in the bloodstream or, less commonly the lymphatic system. When these cells reach a new area of the body, they may go on dividing and form a new tumor called a metastasis or secondary tumor. The most common places for prostate cancer to spread are to bones such as the spine, pelvis, thigh bone (femur) and ribs. Usually, the cancer cells will spread to a number of different places in the bones rather than to a single site. Sometimes prostate cancer can affect the bone marrow. This is the spongy material that’s found in the center of most bones. It’s also where the body’s blood cells are made. Prostate cancer can also spread to thelymph nodes, and occasionally it may affect the lungs, the brain and the liver.
The number of men being diagnosed with cancer of the prostate gland has increased in recent years. It is thought that the incidence is increasing because more men are having tests that detect very early prostate cancers that would previously not have been found. It may also be because the number of older men in the population is growing.
Researchers are trying to find out more about the causes of prostate cancer. Although the causes of cancer of the prostate are still unknown, there are some factors that are known to increase a man’s chance of developing the disease.
Age
This is the strongest risk factor for prostate cancer. Men under 50 have a very low risk of prostate cancer, but their risk increases as they get older. It’s estimated that around 80% of men in their 80s will have some degree of prostate cancer.
Ethnicity
Some ethnic groups have a greater chance of developing prostate cancer than others. For example, black African and black Caribbean men are more likely to develop prostate cancer than white men. Asian men have a lower risk of developing it.
Family history
Men who have close relatives (a father, brother, grandfather or uncle) who have had prostate cancer are slightly more likely to develop it themselves.
It is thought that a man’s risk of developing prostate cancer is higher if:
- their father or brother developed prostate cancer at or under the age of 60
- more than one man on the same side of the family has had prostate cancer.
If this is the case in your family, it may indicate that a faulty gene is present. A specific gene linked to prostate cancer has not yet been identified. However, research has shown that faulty genes that are linked to a higher risk of breast cancer (called BRCA 1 and BRCA 2) may also increase the risk of getting prostate cancer. So, if there’s a strong family history of breast cancer on the same side of the family (especially before the age of 40), it could also indicate that a faulty gene may be present.
Only a small number of prostate cancers (5-10%, or less than 1 in 10 cases) are thought to be due to an inherited faulty gene running in the family. If you are worried about your family history see our section about cancer genetics and prostate cancer.
Diet
There’s often a lot of information in the press and on TV about diet and cancer. There is no single ‘superfood’ or special diet that can give you complete protection from getting cancer. However, eating a healthy balanced diet that’s high in fiber and low in fat and sugars may reduce your risk of getting certain types of cancers and other illnesses. Men from western countries, such as the UK and USA, have a higher rate of prostate cancer than men from eastern countries such as China and Japan. It’s thought that this might be because western diets tend to be higher in animal fat (including dairy products) and lower in fresh fruit and vegetables. Asian men also tend to have a higher intake of soy in their diet. Soy and soy products contain chemicals called phyto-estrogens. Researchers believe these might reduce the risk of prostate cancer, but more research is needed to confirm this.
A high intake of calcium (such as from dairy foods) may increase the risk of developing prostate cancer. However, it’s important not to cut dairy products out altogether, as they provide essential calcium for healthy bones.
Research studies have looked into whether tomatoes and tomato products (such as ketchup) may help to protect against prostate cancer. This may be because they contain high levels of a substance called lycopene. Studies so far have shown mixed results and more research is needed.