Prostate cancer

The prostate is a gland found only in men that produces the liquid component of semen. Prostate cancer is the second most common cancer in men (after lung cancer), though it mainly affects older men.

Caught at an early stage, there is a good chance it can be cured, with treatments tailored to the individual patient and his particular cancer.

The prostate is about the size of a walnut and is located just below the bladder. It surrounds the tube that carries urine from the bladder and out through the penis (the urethra). See the diagram, below.

Changes to the prostate

Normally, cells grow and multiply only when the body needs them to. Cancer develops as a result of a breakdown in this process, leading to cells growing in an uncontrolled way. The mass of excess cells forms a tumour (growth), which may be benign or malignant. The tumour is described as malignant if it is able to invade other healthy tissue.

The peripheral (outer) zone of the prostate is the area most susceptible to developing cancer.

Prostate cancer is rare in men under 50 years old. However, the risk increases steadily with age and by the time they are 80, more than half of all men will have some cancerous growth, though in most cases it goes unnoticed. Prostate cancer is usually slow-growing and, in men who have it, it is often not the cause of death.

The causes of prostate cancer are largely unknown. It is clear that the chances of developing prostate cancer increase in men over 50. Close relatives of men who have had prostate cancer are also more likely to be affected. Ethnic origin appears to play a part: black men seem to be at highest risk, and men of Far Eastern descent the lowest.

It may be possible to reduce the risk by avoiding a high fat diet through, for example, cutting down on dairy foods and red meat.

Prostate cancer often has no symptoms. Sometimes, even when symptoms are present, men do not seek medical advice. However, if prostate cancer is found early, it can often be cured.

The symptoms are similar to those produced by a common disease of the prostate, benign prostatic hypertrophy (BPH), and include:

If you develop any of the above symptoms, you should consult your GP. You may then be be referred to a hospital specialist (a urologist).

There are several tests that you may undergo as part of the diagnostic process. Some of these tests may also be performed as part of a routine health assessment.

Urine test

A simple urine test will be carried out to look for blood or infection.

PSA blood test

Testing a blood sample for the amount of prostate-specific antigen (PSA) plays an important part in the early detection of prostate cancer. If an abnormally high level of PSA is detected in the blood, prostate cancer is a possibility. However, a high PSA score does not always indicate cancer and can be caused by other prostate diseases such as benign prostatic hypertrophy or prostatitis (inflamed prostate).

Digital rectal examination

The urologist will carry out an examination of your prostate by inserting a finger into your rectum. Although this can be uncomfortable, it is not painful, and tumours can often be felt by this method. Many men find this embarrassing, but remember that urologists do this as an everyday procedure - and it may save your life.

Biopsy

The urologist may do a prostatic biopsy (removal of a small piece of tissue). A biopsy involves passing an ultrasound probe into the rectum to give an accurate view of the prostate. Samples of the prostate are collected using a needle. Biopsies can be uncomfortable and you may be given a mild sedative or local anaesthetic.

A pathologist will examine the prostate sample under a microscope and check whether or not it is cancerous. If cancer is found, the pathologist will "grade" it. A scale known as the Gleason's score is used. This gives you and your doctor an idea of how quickly your cancer is likely to progress.

Scans

To establish whether the cancer has spread (metastasised) to the bones, you may have a bone scan - a form of X-ray picture.

Another technique is an MRI scan which can look at the body in sections using a strong magnetic field and radio signals. CT scanning is similar to an MRI scan but uses X-rays to build up a picture.

These scans usually look for the spread of cancer to lymph nodes in the pelvis. This helps the doctor to decide how far the cancer has spread (if at all), and therefore the best course of treatment. This process is known as "staging" the cancer.

The most appropriate treatment for you will depend on several factors including:

Watchful waiting

Sometimes, particularly for slow-growing tumours, no treatment is the best course of action. Your condition will be monitored closely with routine check-ups. Some people, however, find this approach causes too much anxiety and will prefer to have some sort of treatment.

Surgery

Surgery is the main treatment for most prostate cancer. The most common technique is a "radical prostatectomy", which involves removing the prostate gland, seminal vesicles and nearby lymph nodes. It is a major operation, so it is most suitable for otherwise healthy men (usually, those under 70) whose cancer appears not to have spread.

About 80% of men who have this operation are still alive after 10 years. Possible side-effects of the procedure include some urinary incontinence, sterility and erectile dysfunction (impotence), although modern surgical techniques can minimise the risks of this to some extent.

Hormone therapy

Hormone therapy successfully reduces the size of prostate tumours in 80% of men, but it does not kill cancer cells. For many men, it will be recommended as well as surgery. It is sometimes used before radiotherapy (see below) to reduce the size of the tumour.

Hormone therapy is based on reducing the level of testosterone, the male hormone produced by the testicles, which stimulates cancer growth. This is done either by "switching off" the production of testosterone, or by damping down the levels that circulate in the bloodstream. This can be achieved with medicines, such as finasteride (Proscar), that block the conversion of a natural chemical into active testosterone. Alternatively, orchidectomy - surgical removal of both testicles, stops the production of testosterone.

Radiotherapy

Radiotherapy is an alternative to radical prostatectomy. Currently there is no conclusive evidence to show that one method is more effective than the other. The treatment involves radiation being applied to the affected areas to destroy the cancer cells. This is usually done as an out-patient procedure. The main side-effects are bladder irritation and diarrhoea. Some men also become impotent as a result.

Brachytherapy

Brachytherapy is a relatively new procedure which involves implanting radioactive pellets into the prostate, where they gradually lose their radioactivity over a period of months. The pellets are inserted under general or spinal anaesthetic. Brachytherapy is not recommended for men whose cancer has spread to other parts of the body.