Inviting men with no symptoms to a one-off PSA test for prostate cancer does not save lives, according to results from a ten-year Cancer Research UK-funded trial.
Researchers at both Bristol and Oxford universities, UK, found that having asymptomatic men take a PSA test detects some disease that is unlikely to cause any harm; however, it misses some aggressive and lethal prostate cancers.
This finding has highlighted the flaws of a single PSA test as a means of screening for prostate cancer and demonstrates the need to find more accurate ways to diagnose cancers that require treatment.
The largest ever trial
The CAP trial is the largest ever to investigate prostate cancer screening, spanning nearly 600 GP practices in the UK and including more than 400,000 men aged 50-69 years.
It compared 189,386 men who were invited to have a one-off PSA test with 219,439 men who were not invited for screening.
After an average of ten years follow-up, there were 4.3% prostate cancers in the screened group and 3.6% in the control group.
Crucially, both groups had the same percentage of men dying from prostate cancer (0.29%).
Finding a cancer that wouldn’t cause harm
While some prostate cancers ae aggressive and lethal, others are clinically insignificant and will never lead to any harm or death if left undetected.
Finding a cancer that would never cause men harm in their life can have a serious impact on quality of life, including worry of a diagnosis, possibility of infection following a biopsy, and incontinence following treatment.
Professor Richard Martin, lead author and Cancer Research UK scientist at the University of Bristol, said: “Our large study has shed light on a highly debated issue. We found that offering a single PSA test to men with no symptoms of prostate cancer does not save lives after an average follow-up of ten years.
“The results highlight the multitude of issues the PSA test raises – causing unnecessary anxiety and treatment by diagnosing prostate cancer in men who would never have been affected by it and failing to detect dangerous prostate cancers.
“Cancer Research UK is funding work that will allow us to follow the men for at least a further five years to see whether there is any longer-term benefit on reducing prostate cancer deaths.”
Should the PSA test be offered?
Dr Richard Roope, Cancer Research UK’s GP expert, said: “The PSA test is a blunt tool missing the subtleties of the disease and causing men harm.
“We do not recommend that the PSA test should be routinely offered to men without symptoms. However, if a man is particularly worried about his risk of prostate cancer, he should have a full discussion about his risk with his GP.”
There is no national screening programme for prostate cancer in the UK, but men over 50 can ask their GP for a PSA test.
Prostate cancer was recently revealed to be the third biggest cancer killer, overtaking breast cancer.
Source: Cancer Research UK