Prostate Cancer Fact File
by Peter Lavelle (ABC Health library A -Z , HEALTH MATTERS
Published 15/05/2003

Background
For such a seemingly innocuous organ, the prostate gland can cause a lot of trouble in older men. Men in younger age groups can sometimes be affected as well.

About the size of a walnut, the prostate is situated at the base of the bladder. It's not high on the list of vital organs, not being essential for life, but its function is to produce the ejaculate fluid in which sperm bathes. (It's thought that the fluid nourishes and activates the sperm and then helps transport it through the urethra during and after sexual intercourse, and later in the vagina and uterus.)

But in men over the age of 50, the prostate makes its presence felt because it gets bigger. This enlargement can obstruct the passage of urine, causing problems with urination like difficulty in getting started, dribbling or slowness in passing urine, and sometimes pain, blood or incomplete emptying of the bladder. The most common complaints are problems in passing urine due to non-cancerous enlargement of the prostate called Benign Prostatic Hypertrophy, or Benign Prostate Hyperplasia (BPH).

Prostate cancer is another (more serious) cause of these symptoms. Although it is less common than BPH, it is nevertheless, as cancers go, very common. In Australia it is the most common type of cancer in men after skin cancer.

Not much is known about why cancer develops in the prostate in some men. It's a disease of older men - it is rare under the age of 50. But when it does occur in men under 50 it is more likely in a man with a family history of prostate cancer. It has been found to be associated with certain diets - including diets high in animal fats, low in plant food, and possibly low in certain elements, anti-oxidants and vitamins, as well as occupational exposure to certain substances including cadmium and rubber.
Symptoms
In the early stages, when the cancer is quite small, there are no symptoms. In fact, it can take five or more years of growth before an enlarged prostate produces any symptoms.

The first symptoms are usually some form of difficulty in urination. That is because the urethra, the thin narrow tube that connects the bladder through the penis and to the outside world, passes through the middle of the prostate (surely one of the stupidest designs that have ever evolved). As it grows, the tumour tends to expand into this passageway, disrupting the smooth passing of urine, producing the following symptoms;

difficulty in starting urine flow
a slow interrupted flow and dribbling afterwards
frequent passing of urine, especially at night
pain during urination
blood in the urine.
These are similar to the symptoms caused by the more common condition, benign prostatic hypertrophy (BPH), so establishing the correct diagnosis can be confusing.

However, because the chance of a cure is much greater if prostate cancer is diagnosed in its early stages, anyone with these symptoms should see their GP without delay. If it does turn out to be BPH this condition can be treated, with good symptom relief.

Like most other types of cancer, as prostate cancer grows it can spread beyond its site of origin into other tissues or organs nearby, such as the rectum or bladder. It can also spread to lymph nodes in the pelvis or via the bloodstream to distant organs - the bones (especially the pelvic bones and lower spine), lungs, or even the brain.

Thus if the cancer is advanced, there may be symptoms associated with this spread to other places, such as pain in the lower back from cancer in the spine. There may also be generalised symptoms like tiredness and weight loss.
Diagnosis
If the doctor suspects there could be a problem with the prostate, he or she will do a rectal examination. This involves the doctor placing a gloved finger via the anus into the rectum and feeling the prostate. If its larger, lumpy or harder than normal it could be cancerous. (An enlarged prostate that is not hard or lumpy is probably a result of BPH.)

The only certain way of diagnosing prostate cancer is with a biopsy of the prostate. So if the symptoms and a rectal examination and a positive PSA test (discussed below) suggest the possibility of prostate cancer, the GP will send the patient to an urologist for an opinion. If the urologist believes it could be prostate cancer, a prostate biopsy will be arranged.

This biopsy is usually done by inserting an ultrasound probe via the anus into the rectum. The ultrasound helps give a picture of where the cancer is within the prostate, helping the urologist to know where to insert the needle into the prostate to extract cancer tissue. The urologist sends the tissue to a pathologist for examination.

If the biopsy shows cancer is present, then other tests such as a bone scan will be done to determine if and where the cancer has spread.

The PSA test is a blood test that can help detect some prostate cancers. The prostate produces a substance called Prostate Specific Antigen (PSA) which is thought to aid sperm movement. This is released into the bloodstream. A prostate cancer usually releases PSA in abnormally high amounts. The PSA test measures the level of PSA in the blood. If it is abnormally high, it may indicate the man has prostate cancer.

However, the PSA level is also abnormally elevated in some other conditions - including infections of prostate, and especially BPH. A raised PSA test alone therefore is not conclusive of prostate cancer. Only about one in three men with a raised PSA will be found to have prostate cancer, although the higher the level of PSA, the more likely it is due to cancer.

In fact, the PSA test alone is so unreliable that some Australian health authorities don't advise men to have it as a screening test for prostate cancer. Many men do have the PSA test and many doctors recommend it as an indicator to carry out further tests if it is abnormally raised, and especially if in successive tests it continues to rise.
Treatment
There are various options for treating prostate cancer, depending on the extent of the cancer, in particular whether it is localised to the prostate gland only or has spread into surrounding tissues or to other parts of the body.

Other important considerations are the age and general health of the man, and how aggressive and rapidly growing the cancer cells are. The pathologist can usually give an indication of this from examination of the cancer cells in the biopsy specimen.

If prostate cancer is diagnosed at an early stage and confined to the prostate gland, the prostate with the cancer may be surgically removed. Usually the whole prostate (including the cancer) is removed along with the seminal vesicles (two small sperm storage sacs at the back of the prostate).

After the operation - known as radical prostatectomy - more than 75 per cent of men will remain disease-free for 10 years or longer, but most men will be left with at least some degree of impotence and about half will have some degree of urinary incontinence.

Radiotherapy can be an effective alternative and is followed by lower rates of impotence and incontinence, but radiation colitis - inflammation of the bowel and rectum - is a common side effect, often leaving the patient with poor bowel control.

An alternative is not to have an operation but to wait and see what happens - this is sometimes called 'watchful waiting' or 'watchful expectancy'. Prostate cancer is the most common form of internal cancer in men, but it usually grows quite slowly. After diagnosis, the majority of men will survive for at least five years, or even as much as 10 years or more. If the man is elderly, and at the age of diagnosis his life expectancy is not so great anyway, he may die of something else. In other words, he will die not from prostate cancer, but with prostate cancer.

In fact studies have not yet conclusively proven there is a significant difference in survival rates with either approach - surgery or 'watchful waiting' - especially in older men. Surgery reduces the chance of death from prostate cancer in the younger and fitter age group, but men in the older age group may be more likely to die of something else anyway.

So for a man with treatable prostate cancer, the dilemma is: Should I have it treated, risk possible side effects from the surgery, but (possibly) prolong my life? Or should I not have it treated, maintaining the quality of my life but with the risk that the cancer could spread and become incurable?

Often the decision comes down to age. In older men, if the cancer is at an early stage, it may be sensible to do nothing but wait and see how it develops. In younger, fitter men it would usually make sense to have it treated more aggressively with surgery or radiotherapy.

Each person needs to make their own decision with the help of their doctor, based on their own circumstances and life priorities. Younger men should take into account the probability of increasing their life expectancy, but at the cost of possible sexual impotence and possible urinary incontinence. (Sexual impotence due to erectile dysfunction can be well treated, but the spontaneity of sexual intercourse is lost.)

If the disease is advanced locally into surrounding tissues or if it has spread to other areas of the body, a cure is not possible and treatment is aimed at slowing the growth of the cancer and improving and maintaining quality of life for as long as possible. Radiotherapy will usually achieve good control of a locally advanced cancer, possibly for several years, and may also be helpful in controlling a painful secondary spread of prostate cancer in a bone; but for more widespread cancer, hormone treatment, or even chemotherapy, may be needed to achieve relief for a greater or lesser period of time.

Prostate cancer, like the normal prostate, is influenced by male hormones (androgens). Treatments aimed at reducing male hormones in the blood will slow the growth of the prostate cancer. Reduced levels of male hormones may be achieved by surgical removal of both testes (bilateral orchidectomy, or castration - usually not a popular choice of treatment), hormone therapy using injections or tablets, or in some advanced cases, by chemotherapy.
Reviewed by Professor Fred Stephens, Emeritus Professor of Surgery, The University of Sydney
Last modified 15/05/2003

by Peter Lavelle from ABC Health Matters Online at http://www.abc.net.au/health