Prostate cancer
Written by Dr Russ Hargreaves, PhD, Director of Support and Information, The Prostate Cancer Charity, London UK
What is prostate cancer?
Prostate cancer is a disease that affects men from around the age of 45 years. It involves the prostate gland, which is a small gland about the size of a walnut, positioned just beneath the bladder, and is responsible for producing fluids that nourish and protect sperm (see Figure 1).
Since the urethra (the tube that carries urine from the bladder) passes through the centre of the prostate gland, any growth within the gland will cause pressure on the urethra, causing difficulties in passing urine.
The disease is the commonest male cancer in the UK. Around 20,000 men in this country are diagnosed each year. Sadly, approximately 10,000 British men die of prostate cancer every year, so it is a disease that needs to be taken very seriously. Because we do not routinely screen for prostate cancer in the UK, the disease is very often detected only when it has spread away from the prostate gland to other parts of the body.
Why or how do I get prostate cancer and how can it progress?
It is still not entirely clear why some men develop prostate cancer and others do not. However, we do know that there are both genetic and environmental factors that can influence it.
In terms of genetic factors, you have a higher risk of developing prostate cancer if your father or brother had prostate cancer, although the increased risk is relatively small.
Perhaps more important are environmental factors such as diet and lifestyle. Vegetarians are half as likely to develop cancer as meat eaters. When we look at geographical differences, people living in the Far East such as the Chinese and Japanese have an extremely low risk of developing prostate cancer compared with those who live in Western countries such as America and Britain.
Scientists are currently investigating whether certain dietary factors may help to prevent prostate cancer. Much of this work is focussing on the mineral selenium and a substance from processed tomatoes called lycopene. Several very large studies have shown that both these agents lower the risk of developing prostate cancer.
* You cannot catch prostate cancer through sex, nor can you infect your partner with prostate cancer.
* Smoking is not linked to the occurrence of prostate cancer.
* Vasectomy was once thought to predispose men to prostate cancer but this is no longer considered to be the case.
Prostate cancer generally takes a long time to progress and it can take 10 years before it is detected. However, some men have a particularly aggressive form of the disease, and the disease can grow and spread more quickly. The cancer has a great tendency to grow on the outside edge of the prostate gland and can therefore easily break away from the gland itself. Once it does this, it tends to travel almost exclusively to the bones including the hip bones, lower spine and ribs.
What are the symptoms?
If the prostate gland grows significantly for any reason, it can put pressure on the urethra, and this may cause various problems. Common symptoms include:
* frequent visits to the bathroom to pass urine (frequency)
* having to wake up regularly throughout the night to pass urine (nocturia)
* a sense of urgency in getting to the bathroom in time (urgency)
* hesitation before the urine begins to flow (hesitancy).
* pain while passing urine
* blood in the urine
* impotence (erectile dysfunction) (inability to sustain an erection)
* hip or lower back pain.
It is very important to emphasise that the presence of such symptoms does not necessarily mean you have prostate cancer. Indeed, any problem with the prostate will generally lead to some of these symptoms, which can include prostatitis - a prostate infection - or benign prostatic hyperplasia (BPH) - a non-cancerous enlargement of the prostate gland. However, if you do have any of these symptoms, please consult your doctor since the earlier they are treated the better.
Equally important to emphasise is that many men, especially those in the early stages of the disease, do not develop symptoms at all. Therefore, a lack of symptoms does not always mean that you are free from the disease, and further tests will be needed to confirm this.
How is prostate cancer diagnosed?
There are two very simple and painless tests that can help to diagnose prostate cancer. Firstly, a test will be carried out to measure levels of prostate specific antigen (PSA) in the blood. The other test that can be carried out is a digital rectal examination (DRE).
* PSA is a protein produced exclusively by the prostate gland. All men have a small amount of PSA in their bloodstream (around 4ng/ml). If this level rises, and it can reach 3000ng/ml or more in some men, your GP may wish to refer you to a specialist for further tests.
* A DRE involves the doctor placing a finger inside your back passage and feeling the prostate gland to check its size and shape and whether any lumps can be detected. Although not very pleasant, this should not hurt in any way.
Although neither test is 100 per cent accurate, taken together they can alert the doctor to any possible concerns. Your doctor may also take into account your age, since prostate cancer generally affects men over the age of 50 years, and he may also ask about any family history of prostate cancer.
What else could it be?
A raised PSA does not necessarily mean that you have prostate cancer. Almost any condition that causes the prostate gland to grow or swell will result in a raised PSA test result.
PSA also rises slightly as you get older. Similarly, a DRE can be very difficult to interpret and may require the expertise of a doctor with specialised knowledge.
What can your doctor do?
If a prostate gland feels large and smooth on a DRE, then this generally indicates BPH, which is not life threatening and can be treated in many ways. However, if it feels lumpy, then there may be cause for concern and this will require further tests.
Equally, the PSA result can be high in men with BPH or prostatitis as well as in those with prostate cancer. There tends to be a very grey area when the PSA is between 4 and 10ng/ml, and such a result could indicate various prostate conditions. However, if the PSA increases above 10ng/ml, your doctor will almost certainly want to send you for further tests.
Always take a pen and notepad (or perhaps your partner or friend) to the consultations that you have with your doctor. This will enable you to remember what has been said to you and will help you discuss your condition with others later on.
In men with suspected cancer, a referral is usually made to a specialist known as a urologist. The urologist will usually repeat some of the tests that you have already had and may then carry out a rectal ultrasound and biopsy to understand the cause of your symptoms. Here, a small probe is placed inside the back passage, which emits ultrasound waves (similar to those used to see unborn babies in the womb) that provide an image of the prostate gland and its surrounding tissue. The urologist can then insert tiny needles into the gland to take small biopsy samples.
This tissue can then be analysed under a microscope to give a much clearer understanding of the cause of the problem. You will be given antibiotics during this time to prevent any possible infections after the biopsy. You may also notice a small amount of blood in your urine or faeces. This is not usually a problem, but if it persists you must consult your doctor.
How is prostate cancer treated?
If prostate cancer has been detected in the biopsy specimens, you now have several difficult choices to make with regard to treatment. The way the disease is treated depends on many factors, including your age and the size and grade of your cancer.
The biopsy specimen is often given a score (1-10, known as a Gleason grade, with a score of two representing the least aggressive form of the disease and a score of 10 the most aggressive cancer.
Very often, the lower-grade cancers can be left alone and will not grow significantly or spread. However, higher-grade cancers (particularly those over a Gleason grade of seven) will often be treated with either surgery or radiotherapy.
Another important factor is whether the cancer is fully contained within the prostate gland or whether it has spread to other parts of the body.
Surgery
For localised cancers (those which are contained) it is possible to remove the entire gland in an operation called a radical prostatectomy. Here, the surgeon makes an incision in your lower abdomen and takes out the whole prostate gland and then re-connects your urethra to your bladder. This is a tricky operation and requires a very skilled surgeon to avoid cutting through the nerve bundles that surround the prostate gland. Because of the likelihood of some nerve damage, impotence is a common problem, and around 70 per cent of men will not be able to achieve a natural erection after the operation.
There is also a slight risk of incontinence, with around 40 per cent of men experiencing minor dribbling and approximately 2 per cent of men requiring the long-term use of incontinence pads. However, surgery is one of the best-tested treatments and is thought to be very effective, provided that the cancer is contained within the prostate gland.
Radiotherapy
This technique can also be used to treat contained cancers. It can be done in several ways. In external beam radiotherapy, radioactive beams are aimed at the prostate from outside the body. However, radiotherapy beams cannot distinguish between normal and cancerous cells, so the beams need to be focussed very carefully on the prostate gland itself.
A newer method, known as 3D conformal radiotherapy, is now used in many hospitals. This technique involves feeding the co-ordinates of the prostate (size, shape, position) into a computer, which then shapes the beams to fit the prostate to limit the damage to normal tissue.
There are fewer side effects with this treatment, with around 40 per cent of men becoming impotent and around 2 per cent of men experiencing incontinence. Because 3D conformal radiotherapy has only been available for a few years, we are not certain of its effectiveness, but studies should be completed soon to give a fuller understanding.
Brachytherapy
This is type of radiotherapy involves placing radioactive seeds inside the prostate gland itself, thereby delivering radiation directly to the cancer.
In this procedure, the doctor inserts needles into the prostate gland under anaesthesia and then passes the seeds through the needles into the gland, where they remain forever. The seeds eventually lose their radioactivity and become ineffective. Because there is no need for surgery, the procedure can generally be carried out in a day or two, and you should be able return to normal life immediately.
Around 3 in 10 men will become impotent after brachytherapy, and a small number of men will experience a burning sensation while urinating, although this normally disappears within weeks.
Brachytherapy in its current form is a relatively new technique, but new studies have monitored men for 10 years and found it to be comparable to surgery in its ability to destroy the cancer.
Watchful waiting
Because some cancers grow very slowly, it is sometimes appropriate to do very little. Known as watchful waiting, this is especially appropriate for men in their 70s whose cancer may grow so slowly that it will not alter their life expectancy.
However, it can be very difficult to be told that you have cancer and that it is not going to be treated. It is important to remember that your doctor will continually monitor the progression of your cancer through PSA tests and will act if necessary to prevent it from spreading.
Hormone therapy
If the cancer has already spread from the prostate gland by the time it has been detected, it will normally be treated with hormone therapy.
Prostate cancers require the male hormone testosterone to grow and spread. Therefore, if you deprive the cancer of testosterone, the cancer is starved. Hormone therapy does just that, and although it will not completely remove the cancer, it can place it on hold for several years and can relieve a number of symptoms including bone pain and urinary problems.
Hormone therapy can also be used in men whose cancer has spread slightly, because this treatment can kill some of the cancer and will shrink the remaining gland, making it easier to then be treated with either surgery or radiotherapy.
How do you live with prostate cancer?
Ironically, prostate cancer itself may not cause you too many problems, whereas the treatment of the disease itself may do.
Many men are diagnosed through screening tests and have no symptoms at all until they are subsequently treated. The most common problems resulting from treatment are impotence and incontinence. However, a diagnosis of cancer is enough to frighten anybody, so you may well experience some psychological effects such as depression.
In most men, impotence can now be treated very effectively with various therapies. It is very important to ask your specialist about the risk of impotence if you would like to maintain a physical relationship. Your doctor can also refer you to an impotence adviser who can help you to find the most suitable treatment for you and your partner.
Incontinence can be more difficult to manage and men often resort to wearing incontinence pads. However, there are other devices, and your doctor can refer you to an incontinence nurse, who will help you find the best solution to the problem. In extreme cases it is also possible to have a surgical operation to minimise incontinence.
Above all, there is no right or wrong way to deal with your diagnosis. If you feel like sharing your experiences with somebody, there are plenty of organisations and support groups that can provide extra information for you, your family and even your friends.
If desired, they can also put you in touch with other men with the condition. It is very important to become informed about this disease before you select a treatment. By arming yourself with knowledge of the various pros and cons of each treatment, you can make an informed choice that is right for you.
Last updated 15.09.2005
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