PSA test used to screen for prostate cancer
The prostate gland, found only found in men, lies just beneath the bladder and its main function is to produce fluid which protects and enriches sperm. The prostate gland gets bigger (enlarges) gradually after the age of about 50 years. By the age of 70 years, about 8 in 10 men have an enlarged prostate gland. It is, therefore, common for older men to have urinary symptoms caused by a non-cancerous (benign) enlargement of the prostate gland. Some men, however, also develop prostate cancer.
Prostate cancer is a cancer which develops from the cells within the prostate gland. In Ireland, prostate cancer is the second most common form of cancer in men, second only to skin cancer. Each year over 3,000 men are diagnosed with prostate cancer, which means that 1 in 8 men will be diagnosed with prostate cancer during their lifetime. Although there are many men with this disease, most men do not die from it. Most cases develop in men over the age of 65 years. Prostate cancer is different to most other cancers because small areas of cancer within the prostate gland are actually very common, especially in older men. These may not grow or cause any problems for many years (if at all).
WHAT IS A PSA TEST?
The PSA test is a blood test that measures the level of PSA in your blood. PSA is made by the prostate gland and the PSA level in your blood stream is measured in nanograms per millilitre (ng/mL). The normal range changes as you get older. The PSA cut-off values for different age groups are as follows:
Age (years)PSA Cut-Off
The higher the level of PSA, the more likely it is to be a sign of cancer. The PSA test can also be misleading and give false reassurance. About 15 out of 100 men with prostate cancer will have had a normal PSA result. As a result a once off test is not reliable and repeating the test may provide important information.
WHAT CAUSES A RAISED PSA LEVEL?
A raised PSA level may mean that you have prostate cancer, however, about 2 out of 3 men with a raised PSA level will not have prostate cancer.
Other conditions may also cause a raised PSA level, including:
- Acute retention of urine (unable to pass urine, causing an enlarged bladder)
- Enlargement of the prostate gland which is non-cancerous (benign)
- Older age
- A urinary infection
- Acute prostatitis (inflammation of the prostate gland)
- Transurethral resection of the prostate (TURP) operation. TURP is an operation used to remove the prostate if you have benign enlargement of the prostate
WHAT HAPPENS AFTER A PSA TEST?
- If your PSA level is not raised: You are unlikely to have cancer. No immediate further action is needed, but you may need further tests to confirm the result.
- If your PSA level is slightly raised: You probably do not have cancer. You will, however, require further tests, including more PSA tests.
- If your PSA level is definitely raised: Your GP will perform a digital rectal examination of the prostate. He or she will also refer you to see a hospital doctor, known as a Urologist, for further investigations in order to find out whether or not you have prostate cancer. The Urologist will usually arrange for you to have a biopsy of your prostate gland in order to confirm the diagnosis and in order to decide on treatment options for the future.
Further information may be obtained from www.cancer.ie