1 in 5 Australian men aged 75 to 84 are being tested each year for prostate cancer, despite international guidelines that recommend against testing in this age bracket.

According to Cancer Council NSW, who will present the research today (16/11) at the Clinical Oncological Society of Australia (COSA) Annual Scientific Meeting, GPs were ordering the tests despite evidence that screening men over 75 for prostate cancer was unlikely to be of benefit.

According to research team leader, Professor Dianne O'Connell, pre-existing evidence suggested prostate cancer in men aged over 75 was slow growing and they were far more likely to die from other causes. "A positive test in this group may do more harm than good," she said.

Even though the majority of men in that age group will have prostate cancer, for most it will never cause a problem. However, the consequence of finding prostate cancer is often that men will opt for some treatment, which carries a high risk of serious side-effects including incontinence and impotency.

"Organisations around the world offer varying guidelines about when men should begin testing for prostate cancer, if at all," Professor O'Connell said. "But there is consensus that from age 75, men who do not have a life expectancy of at least 10 years, should not be screened."

Of the men surveyed in the 75 to 84 years age bracket, 20% had a Prostate Specific Antigen (PSA) blood screening test in the previous year and 35% had one in the previous two years. Screening data was sourced from Medicare claims data.

"We don't have information from doctors about what is driving the decision-making process," said Dr O'Connell. "This should be investigated, along with the reasons why doctors continue to order these tests for men in this age bracket."

COSA President, Professor Bogda Koczwara, said there had been debate worldwide over the value of PSA test. She said the test's founder, Doctor Richard Albin, had recently called it a ''hugely expensive public health disaster'' and ''hardly more effective than a coin toss''.

"While there are disparate views of whether or not the PSA test is of benefit, there is broad concensus that we should not be testing men over age 75," Professor Koczwara said. "So it is concerning that this sound advice is not getting through."

Source: COSA