A UK expert has said that a screening test which can reveal prostate cancer is too unreliable. He said it should not be recommended to patients.

In the UK, Prostate Specific Antigen Testing (PSA) is commonly offered to older men (in private healthcare).

Experts are saying (in the UK) that PSA should not be widely used as it does not seem to clearly benefit patients.

Men who test positive in these tests have the same prognosis as those whose cancer is only spotted when symptoms emerge.

Prostate cancer can be hard to treat successfully because by the time symptoms arise (in aggressive cases) it has already spread beyond the prostate gland itself.

The PSA (blood test) seeks a protein that the prostate cells produce. If levels of this protein are higher than normal, this could indicate either a benign prostate enlargement or the presence of cancer.

The PSA does not, however, tell you whether you have cancer. You still have to have a biopsy operation. Often (after the biopsy) the test is wrong.

Many older men get prostate cancer. The problem here is that most of them would die of something else (old age) rather than the prostate cancer. It is a slow-growing disease. Many of these men would be better off if left untreated (stress here that we are talking about old men).

A positive PSA test can mean that many cancers which could easily have been left untreated with no ill effects for the man are removed by surgeons, creating unnecessary risk - and a chance of disabling side-effects such as incontinence and loss of sexual function.

A growing number of UK experts are doubtful about whether the PSA test should be given to apparently healthy men.

Some companies offer the PSA as a matter of course for men over 50.

Professor Malcolm Law, from the Wolfson Institute of Preventive Medicine in London, wrote in the BMJ that public health authorities should not advocate tests of ’unproven value’.

He said: ’At present the one certainty about PSA testing is that it causes harm.

’Some men will receive treatment that is unnecessary - and the treatment will cause incontinence, impotence and other complications.

’In one study over two-thirds of men receiving either radical prostatectomy (surgical prostate removal) or radiotherapy were affected.’