PSA test for prostate cancer
What is the PSA test?
PSA (Prostate Specific Antigen) is an enzyme (a protein) substance made by the prostate gland. It is made by both normal cells and cancer cells (if present), and is secreted into the seminal fluid to keep it liquid. A small amount of PSA continually leaks from the prostate gland into the blood stream. Cancer cells produce more PSA than normal cells, and when prostate cancer cells multiply, more PSA spills into the blood. The PSA test measures the level of PSA in the blood.
So a raised PSA can be an early indication of prostate cancer. But other conditions, such as benign (non-cancerous) enlargement of the prostate, inflammation or infection, can also cause a rise in PSA, a 'false positive'. And it is also possible to have cancer but have a 'normal' PSA result; this is called a 'false negative'.
Although men did not know much about the PSA test, some of those we talked to knew what PSA stood for and could explain why the test is done.
Explains what PSA stands for and why the test is done.
Explains what PSA stands for and why the test is done.
Suggests that if a man has urinary symptoms a PSA test is a useful way to start investigations.
Suggests that if a man has urinary symptoms a PSA test is a useful way to start investigations.
But many other men we talked to seemed confused and expressed misunderstanding. One man, for example, suggested that too much PSA allowed the cancer to grow, and he said it was important to 'kill the amount of PSA manufactured by the prostate gland'. Some men found it hard to explain what a rise in PSA level in the blood might indicate, and others didn't know what the letters PSA meant.
The PSA test is available in the National Health Service. A small sample of blood is taken from the arm. This is usually done in a GP's surgery or in a hospital clinic. The men we interviewed stressed that it was just like any other 'normal' blood test, but there are advantages and disadvantages of having the test and GPs have been told to inform men about the possible benefits and drawbacks of having a test before proceeding.
Public Health England has developed the Prostate Cancer Risk Management Programme (PCRMP):
The information is available to assist GP's in the counselling of otherwise well men who enquire about testing. It helps the primary care team to provide men with information on the benefits and limitations of the PSA test. It comprises a full evidence document, a summary sheet for primary care teams and a patient information sheet that GPs can print off for men.
For him the PSA test was no problem whatsoever; he went to work five minutes later.
For him the PSA test was no problem whatsoever; he went to work five minutes later.
Well I just went in for a normal blood test. I just went in. A lovely lady sat me down and took some blood from me and said, 'Thank you very much', and off I went to work. And it was fine. It was no problem whatsoever. And I was told to ring in a couple weeks later to find out whether it was, whether my GP wanted to see me again but it was very easy, painless and it was, it was fine. I went to work five minutes afterwards.
Says the PSA test is a normal blood test but is concerned about possible false positive results.
Says the PSA test is a normal blood test but is concerned about possible false positive results.
Well I don't think anybody should be afraid of having it [a PSA test], as it's only a normal blood test. I think you know may be for some people when you say the prostate and it's a test for prostate problems they think that the test involves some squeamish, you know, invasive test on their genitals or something and they don't even realise it's a blood test. I mean I think one has to not assume anything and not assume that people know what a test involves you know. I mean
What did it involve exactly can you explain?
Well it just involved sitting there with the nurse and rolling up my sleeve and having, and she's one of the best nurses I've ever met, I mean she manages to take blood before you even realise she's actually done anything, it's quite remarkable. But most practice nurses are very skilled in that regard, much better than GPs I should say, in my experience. So I think that you know, no one should be put off. I mean it's the same, it's just as straight forward as having a blood test for anything else there's nothing horrible about it and I think it probably is that sort of thing that people should consider even if they don't have symptoms just because it gives you that peace of mind. Having said that though I mean obviously there needs to be a lot of, there needs to be something more done to kind of confirm this issue of false positives and being very careful not to send people into some sort of treatment route or even other invasive investigations based on what might actually be an inaccurate reading. I mean it's interesting that you're pointing out the thing about exercise and having sex and things because that certainly wasn't, I mean this is the first time I've heard that and it would be rather alarming if I'd had a raised reading for some, some reason as innocuous as that. So I think that is a bit of failing really on the part of the practitioner and I think that's something that people should pay a lot of attention to.
A digital rectal examination is often seen as an important part of the prostate examination. Some other factors, such as ejaculation, urinary infection or a prostate biopsy in the last 6 weeks can also affect the PSA level in the blood, making it appear abnormally raised. It is not clear whether or not vigorous exercise, such as cycling, affects the PSA level, but doctors had told some men to avoid such activity just before their PSA test and the PCRMP information also recommends not having a PSA test for 48 hours after heavy exercise.
The doctor at the hospital told him not to ride a bicycle just before his PSA test.
The doctor at the hospital told him not to ride a bicycle just before his PSA test.
Yes then I, then I went to see the consultant and he had a surgery at the hospital that day and one of his assistants examined me further, did another digital rectal examination and found no problems there, he said it was smooth on the outside. But he did explain that sometime cancers can develop inside the prostate and just because the gland was smooth it wouldn't necessarily indicate there was no cancer. But because I'd only had one PSA test at that time he suggested I had another one just in case it was a hype in the system. I also explained to him I had been riding my bicycle before the test and he just said that riding your bicycle can sometimes raise the PSA. Which again I didn't know that was the situation.
So nobody had told you not to ride a bicycle?
No.
Before the test?
No.
Right.
It's just one of those things, apparently it can activate the prostate and cause a possible leap in your PSA reading.
The GP told him to avoid sex and vigorous exercise before his PSA test.
The GP told him to avoid sex and vigorous exercise before his PSA test.
So to avoid cycling?
Yes avoid cycling [laughs] so I had to drive to the GP that day. What else, what else, what else I was able to eat so there was no problem with that, but yeah it was, I think I was given most bits and pieces of information, it was quite straight forward yes.
Some medicines may also affect the PSA result. One man had heard that herbal remedies such as saw palmetto, which is sometimes used for benign prostate enlargement, could artificially 'dampen' the PSA level although there is currently no evidence of this.
Suggests that some drugs and herbal remedies may lower the PSA level in the blood.
Suggests that some drugs and herbal remedies may lower the PSA level in the blood.
What's your understanding of the PSA test?
My understanding of the PSA test that it's, that it's an indicator but it's not foolproof. And I suppose one of, one of the ongoing concerns about the whole thing about prostate cancer is that's its very, very difficult to diagnose prostate cancer other than by physical biopsy. And in fact you know lots of the drugs that you can be given for an enlarged prostate may actually dampen your PSA levels, maybe artificially, so that's sort of an interesting thing that sort of stays in the back of your mind so does, in fact I think you know there's even been the thought that saw palmetto can actually artificially dampen your PSA levels and therefore could mask the fact that you might have cancer. But I think it's quite a contentious issue. I mean I have seen research saying that there are people that have had quite aggressive cancers and have had normal PSA levels until quite well into their, their illness.
In future other more accurate ways to diagnose prostate cancer may be developed. Scientists are continuing to look for new ways to diagnose prostate cancer.
He is adamant that the PSA test gives men a chance of surviving prostate cancer .
He is adamant that the PSA test gives men a chance of surviving prostate cancer .
Now I am a retired nurse amongst other things and I was in charge of a male genitourinary ward and this was in the 60s. What a lot of people don't appreciate without the PSA test, which is really wonderful and fantastic, we would have to go back to the old ways, you didn't know you had prostate cancer until you broke a major bone and what a hell of a way to find out. A PSA test, no matter what people say about it, it is purely an evaluation, it is no more than taking your blood pressure to see if you have a problem with your heart and arteries, it doesn't mean you're going to have a heart attack, it doesn't mean to say that you're going to die. If you go along and you have your urine tested it doesn't mean to say you've got diabetes but it's a damn good idea to find out if you have because at least you can control it and you can live with it. Women have repeated scans for breast cancer and the amount of women who die from breast cancer has been reduced. Having a PSA test does not mean that you won't get cancer and it doesn't mean you won't die from cancer but at least you're given a chance.
Some men gave reasons for having the test while others explained why they had decided not to have one. The men we talked to also explained how they decided whether or not to have the test (see 'Deciding whether or not to have the PSA test').
Last reviewed May 2016.
Last updated May 2016.
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