OFFERING a one-off PSA test for prostate cancer to asymptomatic men does not save lives, according to research funded by Cancer Research UK.
Researchers at the Universities of Bristol and Oxford found that testing asymptomatic men with PSA not only detects some disease that would be unlikely to cause any harm but can also miss some aggressive and lethal prostate cancers.
They conclude that the findings highlight flaws in the use of single PSA tests to screen for prostate cancer and show the need to find more accurate ways to diagnose cancers needing treatment.
The CAP Trial is the largest ever to investigate prostate cancer screening, spanning almost 600 GP practices in the UK and including more than 400,000 men aged 50-69. The trial 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 10 years follow-up, there were 8,054 (4.3 per cent) prostate cancers in the screened group and 7,853 (3.6 per cent) cases in the control group. But both groups had the same percentage of men dying from prostate cancer (0.29 per cent).
More than 11,000 men die of prostate cancer each year in the UK. There is no national screening programme for prostate cancer in the UK but men over 50 can ask their GP for a PSA test.
Cancer Research UK points out that some prostate cancers are aggressive and lethal but others are clinically insignificant and will not lead to harm or death if left undetected. Aggressive cancers need to be identified and treated as early as possible, but diagnosing a non-aggressive cancer can also have a serious impact on quality of life, including the stress of undue worry, the possibility of infection following a biopsy, and impotence and incontinence following treatment.
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.
"This trial illustrates that we need to develop more accurate tools if we want to save men's lives. Cancer Research UK's hunt for finding early stages of aggressive prostate cancer is not over. For example, we're funding research into faulty genes which make some men more likely to develop prostate cancer and studying how these genes could help doctors to identify patients who are more at risk.
"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."