Warning over PSA test
A Government adviser has warned GPs not to use PSA testing in healthy men, after new research showed the test was 'fraught with problems'.
The NHS study, published online in the Annals of Biochemistry, found current methods of PSA testing had 'unacceptable' levels of bias.
The researchers estimated bias of between 5 and 22 per cent, which they warned was enough to have a 'significant impact' on clinical decisions.
Previous research by the same team on behalf of the NHS Prostate Cancer Risk Management Programme found even small variations between tests led to 'significant increases in false-negative and false-positive rates'.
Testing of asymptomatic men for PSA suffered a further blow this week a US study in the Archives of Internal Medicine found it failed to reduce deaths.
Dr James Kingsland, member of the Scientific Reference Group of the Prostate Cancer Risk Management Programme, warned: 'The bottom line is PSA testing should not be used as a screening tool in healthy men it's fraught with problems.'
Dr Kingsland, who is a GP in Wallasey, Merseyside, added he had pushed in his area to have access to tests for free PSA for use in symptomatic men.
Recent research by the same NHS team found tests for free or complexed PSA were more specific than standard testing and helped reduce unnecessary biopsies.
Dr Kingsland said: 'It's something to improve PSA to make it a more sensitive and specific test and it's not a lot more expensive.
'Below 2ng/ml it's likely they do not have prostate cancer and above 10 ng/ml you would want to do a biopsy. It's the area in the middle that's difficult.'
Dr Andrew Roddam, leader of the Annals of Biochemistry study and senior statistician at the Cancer Research UK Epidemiology Unit in Oxford, said: 'Methods in use for PSA have varying degrees of bias and non-equimolarity which can have a significant impact on the clinical decision-making process.'
He said manufacturers were working to solve the problem and within 18 months the tests should reach uniform standards.