Sexual Health Advice - Patient Information Leaflets
PSA test for prostate cancer
What is the prostate gland?
The prostate gland (just called ‘prostate' from now on) is only found in men. It lies just beneath the bladder. It is normally about the size of a chestnut. The urethra (the tube which passes urine from the bladder) runs through the middle of the prostate. The prostate helps to make semen, but this is mostly made by the seminal vesicle (another gland nearby).
Prostate gland enlargement
The most common problem of the prostate is prostate enlargement (also called Benign Prostatic Hyperplasia). This is a benign (non-cancerous) condition where the size of the prostate increases gradually after the age of about 50. By the age of 70 about 8 in 10 men have an enlarged prostate.
As the prostate gets bigger it may cause narrowing of the urethra. This may partially obstruct the flow of urine from the bladder and cause obstructive symptoms such as:The enlarged prostate may also ‘irritate' the urethra and lower bladder causing symptoms such as:
However an enlarged prostate does not always cause symptoms.
Prostate cancer
The symptom of prostate cancer can be similar to benign prostatic enlargement. Prostate cancer is a common cancer in older men. Every year in the UK about 22,000 men are diagnosed with prostate cancer. About 8 in 10 cases occur in men over the age of 65. It is rare in men under 50. Unlike many other cancers, prostate cancer is often present for years without realising it. This is because in many cases the cancer is slow growing and can take many years to cause any symptoms. By the age of 80, more than half of all men will have some cancer cells in their prostate – but only 1 in 30 of them will actually die from it.
What is the PSA test and who might have it done?
PSA stands for Prostate Specific Antigen which is a protein made by the prostate which naturally leaks in to the bloodstream. PSA test is a blood test that measures the level of PSA in your blood.
What does the PSA test tell me about my prostate?
A raised PSA level may be a sign that you have prostate cancer. The PSA level is often raised well before any symptoms of prostate cancer develop. The test can help to detect early prostate cancers, which may have a better chance of being successfully treated than more advanced prostate cancers. As a general rule, the higher the PSA level, the more likely that you have prostate cancer.
However, a raised PSA level can also occur in other prostate conditions such as some cases of benign enlargement of the prostate and inflammation of the prostate (prostatitis). In particular, a PSA level that is mildly or moderately raised has a good chance of being due to a benign condition, but could also be due to prostate cancer. Overall, about 2 in 3 men with a raised PSA level do not have prostate cancer.
Also, if you do have prostate cancer, a single PSA test cannot tell you whether a prostate cancer is slow or fast growing. Similarly, in some cases, the PSA level may be normal even when there is cancer there. Up to 1 in 5 men with prostate cancer have a normal PSA level. Therefore, the PSA test is not always an accurate test for prostate cancer.
What happen if my PSA level is high?
What happens next depends on whether or not you have any symptoms, your personal risk of prostate cancer, how high the PSA level is, and your age (the older you are, the higher your PSA level is likely to be whether or not you have prostate cancer).
As a rough guide, there are 3 main options after a PSA test:
PSA not raised: highly unlikely to have cancer. No further action is needed.
PSA slightly raised: probably not cancer, but might need to repeat the test.
PSA definitely raised: probably need a biopsy to find out if you have prostate cancer.
Biopsy of the prostate
If your PSA level is raised, you may be referred to a specialist for a prostate biopsy. This is because a definite diagnosis of prostate cancer can only be made by taking cells from the prostate and then looking at them under a microscope. A biopsy involves using an ultrasound scanner to guide a metal probe into the rectum (back passage).
The biopsy itself is not always foolproof and 100% accurate. If the biopsy does not show any cancer cells, that does not completely rule out an early cancer. Of every 100 men who have cancer of the prostate, the biopsy will miss the cancer in about 20 of them.
Even if you are diagnosed as having prostate cancer, there is still some disagreement among experts as to when to treat it, and if so, what is the best treatment. For example, there is no proof that treating early prostate cancers helps men live any longer. Most men with early prostate cancer will not die as a result of it, in particular older men in their 70s or 80s, or those with a slow-growing cancer. Also some of the treatments for prostate cancer can cause serious side effects in some cases.
So, in summary, pros and cons of the PSA test?
Possible benefits of having the test:
- It may provide reassurance if the test result is normal.
- It can help to detect prostate cancer before any symptoms develop.
- Treatment in the early stages of prostate cancer could help you live longer and avoid the complications of cancer (although there is no good evidence that this is so).
Possible disadvantages:
- It could miss cancer in the prostate, and falsely reassure you that all is well.
- It could lead to anxiety and a biopsy when you have no cancer.
- It might detect a slow-growing cancer that may never cause any symptoms or shorten your life span. But the diagnosis of ‘cancer' may cause you significant anxiety which could affect your quality of life.
- It may lead you to have treatment for early prostate cancer which might not help you live longer. Also, the main treatments for early prostate cancer do carry some risk and can cause side-effects.
