
The potential for blood tests that detect cancer is huge.
But what if a test is, in some ways, too good? What if it finds cancers that if left undetected wouldn’t cause a person any harm? And what if it’s not possible to know for certain which cancers need to be treated, or who could avoid a life-altering diagnosis and potential long-term treatment side effects?
This is the situation right now with prostate cancer.
There’s no UK screening programme for prostate cancer. That’s because the blood test that would be used – called the PSA (or prostate specific antigen) test – isn’t reliable enough.
Men over the age of 50 with no symptoms of prostate cancer can still ask for the test in the UK. But its use is hotly debated around the world.
Now, a new Cancer Research UK-funded study, from scientists at the Universities of Bristol and Oxford, sheds more light on how unreliable the test is. And it confirms that for men without symptoms, the PSA test doesn’t save lives.
What is the PSA test?
Prostate cancer is the most common cancer in men, with 46,690 cases diagnosed each year in the UK.
The PSA blood test is one of the main ways, along with a rectal exam, that doctors can look for signs of prostate cancer.
The test measures the level of PSA in a blood sample. And while it’s normal for men to have some PSA in their blood, a raised level can be a sign of prostate cancer.
But PSA can be raised for lots of other reasons too, meaning a man might get an abnormal result when he doesn’t have cancer.

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It’s this, combined with the test missing some cancers and finding others that would never cause a man any harm, that makes it unreliable for screening.
What does the new study show?
The CAP trial is the largest to date looking at whether the PSA test can reduce the number of men dying from prostate cancer. It includes over 400,000 men from almost 600 GP practices in the UK. Some practices invited men aged 50 to 69 for a one-off appointment with a nurse where they were offered information about PSA testing and, if they wanted it, the test. The rest operated as normal, and didn’t invite men for the test.
After an average of 10 years, the researchers found that the one-off PSA test led to many more prostate cancers being found. But crucially, the men who had the test were no less likely to die of prostate cancer than the men that hadn’t had it.
This suggests that giving a one-off PSA test to men without symptoms doesn’t save lives from prostate cancer, because it:
- Picks up cancers that are unlikely to cause a person any harm
- Misses cancers that are aggressive and probably would benefit from treatment
Professor Richard Martin, who led the study from the University of Bristol, says the results show that giving a one-off PSA test to men without symptoms “risks diagnosing more men with a cancer that would never have caused them any harm”.
“In some cases, this might mean men unnecessarily living with the stigma of having a cancer and the side effects of treatment that was not needed, such as incontinence and erectile dysfunction, for many years, maybe even decades,” he adds.
This backs up a study from 2013 that pooled data from 5 of the largest and most rigorous trials on prostate cancer screening. It too found that the test leads to many men being diagnosed with a cancer that did not need to be found. And that screening for prostate cancer using the PSA test doesn’t reduce the number of men dying from the disease.

Copy this link and share our graphic. Credit: Cancer Research UK
What’s the problem with finding more prostate cancers?
It seems counter-intuitive to suggest that some cancers would be better off left alone. Especially when early diagnosis can boost treatment success for some cancers. But these overdiagnosed cancers pose a serious problem.
What is overdiagnosis?
Some cancers grow fast and spread quickly, but some grow so slowly that if they went undetected they wouldn’t cause a person any problems. People with these harmless cancers won’t have any symptoms, and they won’t die from the disease.
In other words, it doesn’t matter if the cancer is never found.
When these slow-growing cancers are found they’re said to be overdiagnosed.
Read more: Overdiagnosis – when finding cancer can do more harm than good
Unfortunately, there’s no way of telling apart the cancers that need to be found and treated and the ones that could have been left alone. This means that some patients will receive an unnecessary diagnosis, unnecessary treatment, and the emotional and physical side effects they come with.
Richard Roope, a GP and one of Cancer Research UK’s senior clinical advisors, says this highlights the challenge of diagnosing prostate cancer early.
“Some areas of medicine are very clear cut, others less so,” he says. “PSA testing falls very much into the latter. Prostate cancer comes in many shapes and sizes, ranging from the aggressive to the very slow growing. Unfortunately, no available test will discriminate between these.
“What we know is that giving men without symptoms a PSA test does not change the ultimate outcome if cancer is present, meanwhile any treatment used may produce unpleasant side effects.”
What should you do if you’re worried about prostate cancer?
This study shows that having a PSA test when you don’t have any prostate cancer symptoms comes with some serious risks. If you’re still thinking about having the test, it’s important to get the full picture to help you decide. Our website and your doctor can help.
For those with symptoms, or if you notice anything that’s not normal for you, visit your doctor. In most cases it won’t be cancer, but it’s still best to get it checked.
What next for prostate cancer research?
Over 11,000 men die from prostate cancer in the UK every year. And Professor Martin says it’s here that research must be focussed.
We’re not saying that screening for prostate cancer should be discounted. What we’re saying is PSA testing for prostate cancer is not the answer
– Professor Richard Martin
“Finding a way to detect and successfully treat these cancers, ones that are aggressive and harmful, is what we must continue to strive for.
“We’re not saying that screening for prostate cancer should be discounted. What we’re saying is PSA testing for prostate cancer is not the answer.”
One of the most pressing challenges for researchers is finding a way to distinguish the potentially lethal cancers that need treating from the harmless ones that don’t. This would be an important first step in addressing the problem of overdiagnosis of prostate cancer.
One area that’s showing promise is the use of specialised scans. A type of MRI has shown potential in clinical trials as a way of reducing the number of men who need to go through uncomfortable prostate biopsies. The scans could also help accurately map the size and location of prostate tumours and to identify those cancers that are more likely to be aggressive and need treatment.
Our goal is to save men from harm. This means finding a way to stop men with aggressive prostate cancer dying from their disease by developing better tests and more effective treatments. But as the latest research shows, this also means sparing men with harmless cancers an unnecessary but life-altering diagnosis.
Katie Edmunds is a health information officer at Cancer Research UK
Our research on prostate cancer
- Dr Ivan Ahel: Investigating molecules to improve diagnosis
- Professor Ros Eeles: Understanding the genetics of prostate cancer risk
- Professor Nick James: Running the STAMPEDE trial to find new prostate cancer treatments
Comments
Doug Larsen March 28, 2018
I guess I fall into the group that has been diagnosed with advanced prostate cancer following a PSA test, rectal examination and biopsy. The description is T4 NO M1, Gleeson8, PSA with some metastases. This was in 2015. My treatment has been hormone therapy and radio therapy. I am continuing with hormone therapy and the PSA levels have dropped to zero. I now have yearly checkups where PSA levels are examined after a blood test. My understanding is that eventually hormone therapy no longer becomes effective and the cancer revives. I would like to know how likely this is and whether more effective tests than PSA levels can tell me if the cancer has revived.
I.J.Hofer-Villiers March 28, 2018
I already have prostate cancer, when the Doctor sent me for test the Hospital Doctor said what have you come here for. only to find out that I had a PSA of 7. It was treated with Radio treatment. After MRI scans .
Terry Hopkinson March 27, 2018
I would not be around to write this today if I’d not had a one-off PSA test nearly five years ago. My understanding is that the whole point of the test is to indicate that things could be going downhill so that at least you know it’s worthwhile getting investigated. Consequently my view is that this particular bit of research does nobody any favours and I’m gobsmacked that CRUK have published it.
John Fallows March 27, 2018
This article is misleading as clearly explained in previous posts. Thanks to my visionary GP I had been having annual PSA tests for 20 years with intermittent referrals to the (fantastic) Urology unit at Stepping Hill. Last year my PSA had risen to over 15 which had been set as the trigger point for further investigation. I had an MRI scan & bone scan – which revealed I had cancer to the edge of the prostate but fortunately it hadn’t spread outside or to the bones. A biopsy showed Gleason 7 – which led to a radical prostatectomy.
The point is that the PSA test is an indicator and an MRI and targeted biopsy (if required) are what dictates required treatment (or not). This is only mentioned as an afterthought in the article – my understanding is that it is now best practice in the best centres. I don’t believe there are any serious risks in an MRI scan,
My friend’s GP suggested a precautionary PSA test although no symptoms … PSA 20 … MRI … Biopsy … Op … life saved?
Clearly a better blood test will be a major step forward but let’s not dismiss what we have that works – even if it’s imprecise.
Liz March 27, 2018
test
M J HARNETT March 27, 2018
I agree with disadvantages of a one off PSA,but surely a regular check say 1/2 annually would be better.This would show up a change in level which could be significant.
Julia Berg March 25, 2018
This article doesn’t make it clear if the rectal examination is worthwhile or not.
Can a rectile examination reveal if cancer is present (with or without a PSA test)?
if not, is it only a scan that can diagnose prostate cancer?
In other words, what tests should men ask their doctor for (if over the age of 60) to check?
Many thanks
Chris Falla March 25, 2018
Let no one forget that the first symptoms of prostate cancer are no symptoms.
Katie Edmunds, I believe your article is misleading, very damaging – and bordering on moronic.
You are in a position to reach and influence very many people, but very unfortunately you’ve done it with selective data and opinions, rather than ‘fact on the ground’. Who on earth approved this article for release?
Firstly, you state that no available test will determine between aggressive and slow growth cancers.
For me the test (after PSA and DRE) was a biopsy that led to a Gleason rating which in conjunction with a MRI scan informed my urologist and oncologist on the aggression level and led to my treatment options being explained and actioned.
Secondly, you chose to quote Professor Richard Martin: “We’re not saying that screening for prostate cancer should be discounted. What we’re saying is PSA testing for prostate cancer is not the answer.” So PSA testing is not the answer? If you’ve got a better answer, Professor, we’re all ears.
Let’s bring this back to earth with a post recopied from PCaSO Dorset (below). This is how it actually is ‘on the ground’ all over the country, men being properly informed and tested. What would you say to those 200 men mentioned below?
You should withdraw your article and advise all who’ve read it that unfortunately it has not been considered or researched properly. Don’t forget decisions about lives are at stake here. Accuracy of information is totally key.
‘This report is not only inaccurate but misleading. As chairman of Prostate Cancer Support Organisation (PCaSO) in Dorset which has now offered free PSA testing for men. We have now tested 5,000 men. Of these, 600+ have been referred to their GPs and of those, 200 have either been treated (some with advanced prostate cancer) or have been “put on the radar” through active surveillance. Every man is made aware of the advantages and disadvantages of the test before they make their choice. Those with a low score are also advised that the result is a yardstick to compare with any further PSA tests which we recommend they have. We do not rely on anecdotal stories to support our success as we have received scores of letters from grateful men whose cancers have been identified early enough for a complete cure. The article, through its credulous and selective sorting of the “evidence”, is not only misleading but actually undermines the outcomes that we are trying to achieve. It also makes us question the future credibility of CRUK. Early detection of all forms of cancer is key to successful treatment. Symptoms often appear after cancer has already established itself – a contributing factor, I believe to the 12,000 men who die of it annually’
DONALD LEGGET March 25, 2018
Better to have a REGULAR PSA test every year. I agree a one-off test is not the answer. Just do it regularly.
Peter PHILLIPS March 25, 2018
This is a most helpful article, however it does create concern regarding diagnosis and in particular the identification of a cancer that is non aggressive but is treated aggressively. The MRI non invasive checking is the area that needs concentration of effort to determine accuracy.
Olaniyi Oladapo Timothy Onibiyo March 25, 2018
There should be a men screening ln the UK urgently please.
Bill Burrows March 25, 2018
I am 72 and for some years have had the PSA test once a year . More recently after a rectal exam. my GP prescribed Tamsulosin MR 400mcq which has not prevented dribbling sometime after having a pee. Should I seek to have an MRI scan?
Alan John Williams March 25, 2018
I asked for a voluntary PSA test as I’d read somewhere that if you’re over 50, it was a good idea to have one. If I hadn’t had one, I probably wouldn’t be here today, that was back in 2009, I was told I had cancer, and it was caught early. I had a laparoscopic prostatectomy in 2010, then I was told that it was worse than first thought, following the opp, it was found to have spread into my bladder. Then I was asked if I would like to try a clinical trial to help with research, so I agreed, I had harmone injections for 6 months, followed by radiotherapy for 4 weeks half way through the injections. The good news is that it appears to have worked. I now have a PSA test every 12 months to keep an eye on things, my main point being that if I hadn’t had a PSA test I would probably be dead now, I would rather suffer a biopsy of the prostate after a PSA test to be on the safe side, than not have a PSA test at all. I was 55 when I had my prostatectomy.
Amelie March 25, 2018
Unfortunately, I will not be donating to Cancer Research UK again because of this article. How disappointing. I agree with Chris.
Chris March 25, 2018
You’ve framed your email intro with a reference to Stephen Fry. The PSA test alerted him. It also alerted me (I’m in treatment) as well as thousands of men.
To suggest that men without symptoms should not have the test is irresponsible. 40% of cases are not diagnosed until late stage. Why? The timeline between symptoms and late stage can be negligible.
The issue lies with properly trained GPs and there are some horrendous ones out there. My brother (2.5 times likely to get it because I have) was fobbed of by his GP after I was diagnosed. That GP should be urgently re-trained.
I agree that national screening is not possible, but every man over 50 should offered a baseline PSA test with proper education about the test from GP.
No wonder survival rate in Britain is below the European average, with articles like this one.
Millie March 25, 2018
Whilst I agree more research should be conducted, I strongly disagree that you are implying that the PSA test is unhelpful. Many people close to me have only discovered that they have prostate cancer because of the PSA test and if it wasn’t available then it would be a completely different situation now. What are you suggesting? I disapprove of this article and I am very disappointed with the lack of alternatives. You are indicating that men should not get checked… But tell me, would Bill Turnbull and Stephen Fry agree with that?
Robert bullock March 25, 2018
Thankyou for the infirmation.
Gerald Cornick March 25, 2018
Whilst I agree that a better way of diagnosing prostate cancer should be a priority the most should be made of what we have. Me generally are reticent when it comes to speaking about health matters and the high profile publicity which we are seeing can only help.
I was diagnosed with prostate cancer in September 2007 through a chance comment I made to my GP when visiting him for an entirely separate problem. Whilst my GP thought I was ok through an initial internal (anal) examination a blood test followed by an anal biopsy confirmed prostate cancer. By the time of my diagnosis it was too late for me to have my prostate removed so I went down the road of radiotherapy and hormone treatment.
Thanks to a brilliant team of consultants I have had at the Royal Hampshire County Hospital Winchester and the NHS the cancer is very much being kept under control. When diagnosed my PSA was 18 & the last reading recently was 1.2.
Phil Shergold March 25, 2018
I have a family history of prostrate cancer. My father died of it at the age of 61, my two elder brothers have both have had their prostrates removed. I have a PSA test each year which I have to ask my GP for as it’s not an automatic recall. Each reading has come back lower than the 2 mark since I began having the test. I’m 60 next year & always aware that this strain of cancer may be hereditary. Screening sounds far more productive than the current method of testing which in turn will obviously save time & money.
Michael McClure March 25, 2018
I arrived back in the U.K. aged 68, in September 2014 after working in a highly stressful position. My PSA reading at that time was 37! Way above the advised 4. After a biopsy to check for cancer it returned a negative result. Over the past 3.5 years the PSA readings have slowly reduced – 27 – 19 – 22 – now 12 .5.
Obviously very worrying.
However as a very active cyclist my readings will always be high! Although I have friends, also cyclists with readings below 4.
I will continue to be concerned I have been told that the reduction and ups/downs are a clear indication of no cancer.
Then why is my readings so high?
Rogercharles March 25, 2018
It is a sad sad story.
Steve Mayers March 25, 2018
Very useful analysis, far better quality information than the media present
Helen Rowe March 25, 2018
Thank you for this very informative artical, I was under the impression that a PSA test was the answer for early detection in the battle against prostrate cancer and will pass on what I have learnt to family and friends that this isn’t the whole answer at all. Good luck with your continued work in the battle against this killer.
Yvonne March 24, 2018
Thank you for keeping me up-to-date on the progress of prostate cancer, which seems to be rather a difficult cancer to diagnose, but I have great faith in our laboratory personel to eventually be able to recognise this particular killer and then the battle begins. Continue your very special work, and keep all our men safe.
david mitchell March 28, 2018
I thought this information very useful and confirms my current understanding about the test.