A significant proportion of men who do not have prostate cancer test positive for the disease, according to a recent European trial.

The test measures levels of prostate-specific antigen (PSA) in male urine.

Because testing positively can mean that patients without the cancer have a biopsy or other unnecessary treatment, scientists and doctors are beginning to question the normal screening procedure for prostate cancer.

Other recent studies have shown that being screened may not be beneficial in the long term, and that men who take the test end up receiving too much treatment.

Recent data from the Finnish part of the European trial has shown that one in every eight men who receive the test will show up positive with no prostate cancer present. This holds even when the threshold for a positive result is raised considerably.

Meanwhile, the British Journal of Cancer reported that men who get a false positive are twice as likely not to agree to screening in the future even though they may be at risk of developing the disease.

Experts say more research is needed to make screening more accurate. They reminded people that the signs of prostate cancer can include having to rush to the toilet, difficulty in urinating, urinating more often than before, and pain, blood or semen in the urine.

Men with such symptoms should consult their doctor, or a urologist.

According to study lead author Tuomas Kilpelainen, routine screening was not advisable until scientists know more about the test and the effects it has.

While the UK currently has no organised prostate screening programme, the test is available on request, and its use is increasing.

According to Cancer Research UK's chief clinician, there are evidently two sides to the argument for the use of PSA testing.

Peter Johnson said it was important that older men be able to talk their doctors about the test, and make a decision about whether it is right for them.