Common causes of Prostate Cancer

What is Prostate cancer?

The prostate is a gland found only in men, which lies just below the bladder. The tube through which urine flows from the bladder when you pass water goes first through the prostate gland then out through the penis. The prostate gland can become enlarged in many men as they get older which then causes difficulty with urination.

The job of the prostate gland is to produce fluid which forms part of semen and helps to nourish sperm. The prostate gland sits in front of the back passage or “rectum” which is why if a doctor wants to examine the prostate gland they feel it by putting a finger into your back passage. This is also called a “digital rectal examination” or DRE for short. From feeling the prostate gland the doctor can tell how enlarged the gland is and whether it feels normal or cancerous, this can then provide a picture of prostate cancer if it exists.

Cells in the prostate gland are constantly turning over to replace old with new but sometimes this process can get out of control. Cancer is the name for cells which have lost control of their renewal process and start to grow unchecked. They grow into a group of cells called a “tumour”. As the cells grow they can start to invade surrounding tissues in a “malignant” fashion. Cells can break off the tumour and spread to other sites in the body, usually via the blood stream. The cells can then grow where they have settled, often in distant parts of the body such as the bones or brain. These deposits are often called “secondaries” or “metastases”. These are not new cancers but groups of cancer cells spread from the original or “primary” cancer in the prostate gland.

Most often in prostate cancer this process of tumour growth followed by invasion then metastasis is relatively slow and can occur over many months or years. This is why some men may have prostate cancer but never have a problem because of it i.e. their prostate cancer grows so slowly that other diseases or illnesses (e.g. heart attack or stroke) cause problems or even death before the prostate cancer has developed far enough to cause symptoms or spread from the prostate. With modern treatments many men with early prostate cancer can be cured and in many more the prostate cancer can be controlled and the invasion process slowed even more. Prostate cancer survival rates vary widely around the world, although detection in 3rd World countries is often poorly catalogued.

Causes of prostate cancer?

The cause of prostate cancer is not known. What is known is the characteristics of those men who tend to develop prostate problems. These are known as “risk factors” i.e. men with these characteristics are at greater risk of developing the cancer. However it is important to realise that ALL men are at risk of prostate cancer and even young men who have no history of cancer in their family can develop prostate cancer.

Age
Age is the main risk factor for developing prostate cancer. As men get older they have a higher chance of developing all types of cancer including cancer of the prostate. Prostate cancer is quite uncommon below the age of 50 years however four out of every ten men who are 70 years or older will have the illness. Many of these men will live normally without knowing they have prostate cancer and without it giving them any symptoms or shortening their life span.

Hormones
We know that the male hormones tend to stimulate the development of prostate cancers and prostate cancer is very rare in men who have been castrated before the age of 40 years. This is likely to be because the normal prostate gland is affected by male hormones when carrying out its normal functions in the body. Prostate cancer cells originate and have some features similar to these normal prostate cells including being influenced by male hormones.

Race
Prostate cancer is seen more commonly in certain ethnic groups e.g. African-Americans.

Diet
Diet may have an influence on the development of prostate cancer. Prostate cancer is more common in men who have a “western” diet high in saturated fats. Saturated fats are found in red meats such as beef, lamb etc and in some dairy produce e.g. butter and things made with butter e.g. cakes, biscuits etc., and also in highly processed foods e.g. ready meals. It seems that men who have a diet high in saturated fat are at increased risk of developing prostate cancer. It is also widely believed that a diet high in fruit and vegetables helps to prevent many cancers. This may be through the action of cancer protective chemicals found in many fruit and vegetables known as “anti-oxidants”. This is one of the reasons it is recommended that we include five portions of fruit and vegetables in our diet every single day.

Genetic
Prostate problems also tend to run in some families which could suggest part of the cause of some prostate cancers is genetic or hereditary. If your father or brother has prostate cancer your chance of developing it is about double that of the general population. However only a small number of all prostate cancers are caused by a known faulty gene and most occur at random.

Summary of Prostate Cancer Causes

• Age (prostate cancer is more common as men get older)

• Male hormones (prostate cancers uncommon in castrated men)

• Ethnic group (prostate cancer more common in African-Americans)

• Genetic (prostate cancer can run in families)

• Diet