UK expert urges caution as new cancer test technologies emerge

Prof Bob Steele speaking on stage at Screening Symposium 2023.

Professor Bob Steele from the University of Dundee presents at the Cancer Screening Symposium


Public Health Association of Australia

A leading UK cancer screening expert has urged Australian public health experts to exercise caution and “temper enthusiasm” in the face of rapidly emerging cancer test technologies.

Prof Bob Steele, from the University of Dundee, was influential in the development of bowel cancer screening in the United Kingdom. He is the Clinical Director of the Scottish Bowel Cancer Screening Programme and was the Chair of the UK National Cancer Screening Committee for six years until last year.

In his keynote address to the Public Health Association of Australia’s inaugural Cancer Screening Symposium in Melbourne on 1 August, Prof Steele argued that cancer screening has its downsides including the potential to cause harms. In the face of quickly emerging cancer test technology, he recommended advancing “in a cautious and considered fashion”.

He warned the more than 150 symposium delegates in person and online to steer clear of the temptation to take shortcuts and rely on evidence that a test detects cancer earlier as justification for introducing new screening programmes. Prof Steele argued that population based randomised controlled trials (RCT) demonstrating that a screening test leads to a reduction in mortality should still be the required gold standard.

“In the absence of robust knowledge of the natural history of a specific cancer, stage shift per se is an unreliable surrogate for mortality reduction,” he said.

Prof Steele also explored the evolving use of genomics on medicine in general, and cancer in particular, and the potential implications for cancer detection and screening.

At the moment some genetic mutations result in different testing regimes in the UK and in the future genetic testing might be used to identify those at lower risk of cancer who might need less intensive screening. However, Prof Steele argued not enough is known yet to further incorporate genetic factors into screening.

He outlined that we don’t yet know enough about gene mutation’s “penetrance”, how influential these genetic mutations are in the general population, and how they interact with other risk factors – including environmental risks and other genetic modifiers.

In the meantime, he warned of the potential harms of cancer gene tests, including “creating anxiety, generating potentially unnecessary investigations, stopping people from having children, increasing termination rates, creating insurance difficulties, generating certificates of health and relegating lifestyle changes.”

He also warned that gene tests were usually linked to commercial interests.

Prof Steele also outlined his scepticism towards emerging “multi-cancer tests”.

Trials in the UK are testing the use of circulating DNA in blood to detect cancer, and according to Prof Steele, are showing reasonably good results for sensitivity and accuracy.

However Prof Steele posed the question: “is the purpose of multi-cancer detection to make money, or is it to benefit people and populations?”

Prof Steele reasoned that multi-cancer testing would only be useful if

  1. it could be proven that all cancers detected benefited from early detection;
  2. RCTs demonstrated that it reduced mortality, and
  3. there was also an ability to detect the early signs of cancer before it turns into malignant disease.

“The biggest challenge is to temper enthusiasm – and try and get across the message that screening is a double-edged sword,” he cautioned.

“We need to be very clear what we are doing before we introduce another screening programme.”

With the Australian Government recently announcing a commitment to introduce lung cancer screening, Prof Steele’s assessment of the challenges in introducing a lung cancer screening in the UK were also timely.

Prof Steele noted that there is no doubt that low dose CT (computed tomography) scans will be beneficial for those who are at high risk and engaged to take part. But, Prof Steele warned, the challenge and “screening test” will be the method by which those smokers who are at risk are identified and invited to participate.

“But the big question is – can we identify a whole high-risk population – and invite them?…”

“And it’s pretty certain that whatever we do, we are going to introduce inequalities and that’s kind of something we kind of live with in the screening world. But it’s something that we need to constantly work on to try and minimise.”

He also outlined the need for lung cancer screening to embed smoking cessation, minimise false positives and associated harms, provide adequate scan time and expertise, manage expectations from non-smokers, and quality assure the whole program.

“We have to rise to these challenges because the potential benefits [of lung cancer screening] are enormous.”

PHAA CEO, Adj Prof Terry Slevin, said that Prof Steele’s speech was a powerful reminder that cancer screening is a complex issue. Cancer screening experts needed to focus on getting eligible Australians to participate in existing programs.

“We need to ensure our enthusiasm to encourage people to screen must also be tempered by the importance of informed consent.  It is a fine balance. There are genuine, albeit modest risks with the existing screening programs and people should understand those before agreeing to participate.

“At the moment Australia has three life-saving screening programs – with lung cancer screening on the horizon,” Adj Prof Slevin said.

“Too few Australians take part in our proven, effective programs. While we always need to look towards the future, we need to continue to focus our efforts in increasing uptake and reducing inequalities, not get distracted by rapidly emerging unregulated technologies or commercial interests that haven’t yet proven they can save lives.”



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