No evidence for changing PSA guidelines

With updates to NHMRC guidelines and the Red Book pending, the debate over prostate cancer screening has resurfaced.

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Cancer screening programs are once again in the spotlight, with updated guidelines set to be released in the coming months.

The controversy has resurfaced, in part, thanks to Canadian actor Ryan Reynolds encouraging other 45-year-old men to screen for bowel cancer via a colonoscopy after having a polyp removed.

A video of Mr Reynolds receiving a colonoscopy went viral, with some saying it had probably done more to raise bowel cancer awareness than any other  efforts by the gastroenterological profession.

However, it did spark concern in some quarters that it could cause unnecessary panic. Australia’s bowel cancer screening program covers people aged between 50 and 74 – not 45-year-olds – and primarily uses FOBTs, not colonoscopies.

An article from the ABC, published over the weekend, took the discussion from bowel cancer to prostate cancer by arguing that the RACGP’s Red Book guidelines on prostate cancer screenings were more restrictive than National Health and Medical Research Council (NHMRC) guidelines.

Bond University GP researcher Professor Paul Glasziou, a professor of evidence-based practice and an author on the NHMRC guidelines, disagreed that there was any significant departure in the RACGP guidance.

“The thing they both clearly agree on is that, before men have a PSA test, they should be informed about the benefits and harms of PSA testing … and what we currently know about that, in terms of the evidence,” he told The Medical Republic.

He said the consumer voice in the to-screen-or-not-to-screen debate was often missed.

“This shouldn’t be solely a decision made by either the Department of Health, the college of GPs, or the urologists, because it’s the men who have to suffer the consequences, good or bad, from this,” the said.

“It’s hard to inform them completely – the two-page handout that the college has is very good, but it’s hard information to digest, particularly information about what overdiagnosis means.”

In a study conducted several years ago, a community “jury” of men heard a pro-screening urologist, Professor Glasziou and a neutral scientific advisor prosecute the case for and against increased screening in great detail. A control group received a standard handout.

After a two-day deliberation, the men on the community jury had less intention to screen than the control group, but maintained that all men should be given reasonable information and the chance to make up their own mind.

The minor difference between the Red Book and NHMRC guidelines, Professor Glasziou said, is that the RACGP guidelines were clearer about whether and when doctors should inform men about having that discussion.

“At the moment, there is no strong reason to change either the Red Book or the NHMRC position,” he said.  

“But new evidence, particularly on how to reduce the downside of screening, has emerged.”

Since both documents have come out, there have been developments in the diagnostic process – MRI testing has allowed more men to undergo watchful waiting when early-stage cancers are detected.

The renewed interest in screening protocol comes just as the RACGP is in the process of updating the Red Book, and as the Prostate Cancer Foundation of Australia is doing an expert review of the NHMRC guidelines.

Professor Glasziou himself is part of the team updating the Red Book, which is set to be re-released sometime next year.

The RACGP, for its part, is still firmly against any big changes to screening.

“The risks of overdiagnosis and overtreatment include anxiety, as well as erectile, urinary and bowel dysfunction,” RACGP president Adjunct Professor Karen Price told TMR.

“Specialist GPs are the only medical practitioners that see a whole spectrum of patients, and provide a range of care, from preventive care and early treatment, to often very complex care.

“And when it comes to prostate cancer, we do see a large proportion of asymptomatic men as well as those with symptoms, so we have much broader experience in that sense.”

Urological surgeon Dr Nicholas Mehan said he was hopeful that the updated Red Book guidelines would take the MRI advances into consideration.

“Now, someone will come in with a high PSA, they’ll get an MRI scan and if they have an alternative cause for a high PSA, like a large prostate, and they don’t have any suspicious features on their MRI, those patients often will avoid a biopsy,” he told TMR.

“We are … stratifying patient risk with the use of MRI scans, avoiding unnecessary biopsies.

Another change in recent years is how biopsies are taken.

“We go through the skin under the scrotum rather than through the rectum,” Dr Mehan said.

“So the risk of a severe infection is about one in 1000 now, versus 5% previously.”

Ultimately, the urologist said, the current guidelines were more reflective of the reaction to the overdiagnosis issues of the late 2000s into 2010s.

“No one is saying that we go out and do a PSA on absolutely every man in Australia – what we would recommend is that is that people have a risk-adapted approach,” he said.

“It’s a joint decision made between the patient and the clinician, and the patient should be aware of the potential risks and benefits of PSA testing.”