( By JASCAP )
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About prostate cancer
This booklet is for you if you have or someone close to you has prostate cancer.
If you are a patient your doctor or nurse may wish to go through the booklet with you and mark sections that are particularly important for you.
The prostate gland
The prostate is a small gland found only in men.
It is the size of a walnut and surrounds the first part of the tube (urethra) which carries urine from the bladder to the penis.
A diagram showing the position of the prostate gland
The prostate produces a thick white fluid called semen that mixes with the sperm produced by the testes. It also produces a protein called prostate-specific antigen (PSA) that turns the semen into liquid.
The gland is surrounded by a sheet of muscle and a fibrous capsule. The growth of prostate cells and the way the prostate gland works is dependent on the male sex hormone, testosterone, which is produced in the testicles.
The back of the prostate gland is close to the rectum (back passage). Near to the prostate are collections of lymph nodes. These are small glands, about the size of a baked bean.
What is cancer?
The organs and tissues of the body are made up of tiny building blocks called cells. Cancer is a disease of these cells.
Cells in different parts of the body may look and work differently but most reproduce themselves in the same way. Cells are constantly becoming old and dying, and new cells are produced to replace them. Normally, cells divide in an orderly and controlled manner. If for some reason the process gets out of control, the cells carry on dividing, developing into a lump which is called a tumour.
Tumours can be either benign or malignant. Cancer is the name given to a malignant tumour. Doctors can tell if a tumour is benign or malignant by examining a small sample of cells under a microscope. This is called a biopsy.
In a benign tumour the cells do not spread to other parts of the body and so are not cancerous. However, if they continue to grow at the original site, they may cause a problem by pressing on the surrounding organs.
A malignant tumour consists of cancer cells that have the ability to spread beyond the original area. If the tumour is left untreated, it may spread into and destroy surrounding tissue. Sometimes cells break away from the original (primary) cancer. They may spread to other organs in the body through the bloodstream or lymphatic system.
The lymphatic system is part of the immune system - the body's natural defence against infection and disease. It is a complex system made up of organs, such as bone marrow, the thymus, the spleen, and lymph nodes. The lymph nodes (or glands) throughout the body are connected by a network of tiny lymphatic ducts.
When the cancer cells reach a new area they may go on dividing and form a new tumour. This is known as a secondary cancer or metastasis. Even when cancer spreads somewhere else in the body, it is still the same kind of cancer, and is still named after the part of the body where it started. For example, if lung cancer spreads to the bones, it is still lung cancer, not bone cancer. In that case, it may be said that the person has "lung cancer with bone metastases."
It is important to realise that cancer is not a single disease with a single type of treatment. There are more than 200 different kinds of cancer, each with its own name and treatment.
Types of cancer
The majority of cancers, about 85% (85 in a 100), are carcinomas. They start in the epithelium, which is the covering (or lining) of organs and of the body (the skin). The common forms of breast, lung, prostate and bowel cancer are all carcinomas.
Carcinomas are named after the type of epithelial cell that they started in and the part of the body that is affected. There are four different types of epithelial cells:
- squamous cells - that line different parts of the body, such as the mouth, gullet (oesophagus), and the airways
- adeno cells - form the lining of all the glands in the body and can be found in organs such as the stomach, ovaries, kidneys and prostate
- transitional cells - are only found in the lining of the bladder and parts of the urinary system
- basal cells - that are found in one of the layers of the skin.
A cancer that starts in squamous cells is called a squamous cell carcinoma. A cancer that starts in glandular cells is called an adenocarcinoma. Cancers that start in transitional cells are transitional cell carcinomas, and those that start in basal cells are basal cell carcinomas.
Leukaemias and lymphomas
These occur in the tissues where white blood cells (which fight infection in the body) are formed, i.e. the bone marrow and lymphatic system. Leukaemia and lymphoma are quite rare and make up about 6.5% (6.5 in 100) of all cancers.
Sarcomas are very rare. They are a group of cancers that form in the connective or supportive tissues of the body such as muscle, bone and fatty tissue. They account for less than 1% (1 in 100) of cancers.
Sarcomas are split into two main types:
- bone sarcomas - that are found in the bones
- soft tissue sarcomas - that develop in the other supportive tissues of the body.
Others forms of cancer
Brain tumours and other very rare forms of cancer make up the remainder of cancers.
The information in this booklet covers three types of prostate cancer:
- Early (localised) prostate cancer
- Locally advanced prostate cancer
- Advanced (metastatic) prostate cancer
Prostate cancer generally affects men over 50, and is rarely found in younger men. It is the commonest type of cancer in men. Around 34,000 men in the UK are diagnosed with prostate cancer each year.
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.
Approximately one half of all men in their fifties have some cancer cells within their prostate and 8 out of 10 men (80%) over the age of 80 have a small area of prostate cancer. Most of these cancers grow extremely slowly and so, particularly in elderly men, will never cause any problems.
In a small proportion of men, the prostate cancer can grow more quickly and in some cases may spread to other parts of the body, particularly the bones.
Early (localised) 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 localised 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 has begun to spread outside the prostate gland. In about 1 in 10 men (10%), the prostate cancer will be advanced when it is first diagnosed.
Advanced prostate cancer can also occur in men who have been treated for early or locally- advanced prostate cancer and whose cancer has come back (relapsed or recurred). You can find out more about the stages of prostate cancer.
Prostate cancer cells can sometimes spread beyond the prostate gland (the primary tumour) and travel around the body in the blood stream, 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 tumour called a metastasis or secondary tumour.
The most common place that prostate cancer spreads to is 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 a single site. Sometimes prostate cancer can affect the bone marrow. This is the soft tissue in the centre of most bones and is where the blood cells are made. Prostate cancer can also spread to the lymph nodes and very occcasionally may affect the lungs, the brain and the liver.
We have separate information about the different treatment options for each of the three types of prostate cancer.
Risk factors and causes of prostate cancer
In the UK about 1 in 14 men are diagnosed with prostate cancer in their lifetime. In the USA the incidence is much higher. This is thought to be due to the fact that in the USA more men have tests to try to detect early prostate cancer.
The number of men being diagnosed with cancer of the prostate gland in the UK (and many other countries) has increased in recent years. However, the number of men dying from prostate cancer has not really changed over this time. 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.
The strongest risk factor for prostate cancer is age. 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 prostate cancer.
Some ethnic groups have a higher 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.
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 more likely 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. However, a specific gene linked to prostate cancer has not yet been identified.
If several women in a family have had breast cancer (especially before the age of 40), it could also indicate that a faulty gene may be present. This gene may increase the risk of men in the family getting prostate cancer. 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 in the family.
If you are worried about your family history see our booklet 'Are you worried about prostate cancer?'
It is thought that a diet high in animal fat (including dairy products) and low in fresh fruit and vegetables may increase your risk of prostate cancer. A high intake of calcium (such as from dairy foods) may increase the risk of developing prostate cancer.
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.
How common is the prostate cancer in India?
Prostate cancer is a common cancer among men from the Indian subcontinent, though not as common as it is among men from the developed western countries. The incidence (newly diagnosed cases of Cancer in a year) of Prostate Cancer for men from India is about 4 men per 1,00,000 population1.
In India, between the years 2001-2003, across five urban centers - Mumbai, Delhi, Chennai, Bhopal and Bangalore, – and one rural center - Barshi, a total of 2,215 cases of Prostate Cancer were registered (5.03% of all cancers) for male cancer patients, across all the age groups2.
The TATA Memorial Hospital (T.M.H.) in Mumbai, India registered a grand-total of 10,747 cases of all types of male cancer patients in the year 2006, out of which 261 men (close to 2.5% of the total male cases) were diagnosed with prostate cancer3.
Close to 30% of all Genito-urinary cancers among men in the year 2006 at the T.M.H. were attributable to Prostate cancer.