End of the PSA in the USA?

The era of the PSA (prostate specific antigen) test is over. That, at least, is the conclusion of the official journal of the American Unrological Society.

The Journal of Urology has published a paper from Stanford University school of medicine in which researchers studied prostate tissues collected over 20 years and concluded that the PSA test does no more than measure the size of the prostate gland. It does not explain why it is growing or whether it is dangerous. As a result, they say, many thousands of American may have had their prostates removed needlessly.

Professor Thomas Stamey who led the research told The Guardian that he had come to believe that the PSA test was not a useful predictor of the amount or severity of prostate cancer. He said raised PSA levels may simply reflect benign prostatic hyperplasia — relatively harmless prostate growth. 'The PSA era is over,' he said.

Tumours found 20 years ago were generally so large they generated PSA levels high enough to provide a reasonably good measure of cancer severity. But he said that, as screening became more commonplace, many cancers were being caught earlier and were usually smaller, not generating sufficient PSA to be a good indicator of severity. He said prostate cancer was a disease all men got if they lived long enough.

'Our job now is to stop removing every man's prostate who has prostate cancer,' he told the newspaper. 'We originally thought we were doing the right thing, but we are now figuring out how we went wrong. Some men need prostate treatment but certainly not all of them.' He said the PSA was still useful in monitoring patients after removing the prostate as an indicator of cancer that had spread to other parts of the body.

The PSA test has never been as popular in the UK as in the USA. There is no national secreening programme although the NHS encourages men to discuss the test with their doctor if they have symptoms of an enlarged prostate.

Chris Hiley of the Prostate Cancer Charity says a PSA test that proved positive was likely to lead to a biopsy, and given that 80% of men in their 80s (and even 8% of men in their 20s) have prostate cancer, it is quite likely that cancer would be detected. Men without symptoms who chose to have a test in the first place were probably then more likely to opt for surgery rather than the "watchful waiting" that some experts advocate.

'The intuitively obvious thing is that if you can get in and take the prostate out, things will be fine and dandy, but large numbers of men will be having operations they don't need,' says Dr Hiley. Side effects of that surgey can include impotence and incontinence.

Some 10,000 men die of prostate cancer each year.