Balance urged in cancer screening to avoid health pitfalls

Experts have called for a rethink of cancer screening in the light of improved understanding of the complications and consequent poorer outcomes that can result from overdiagnosis of some cancers.


In a series of articles published in the Sax Institute’s Public Health Research & Practice journal, researchers say a ‘one size fits all’ approach to cancer screening, particularly with prostate cancer, is inappropriate, leading in many cases to patient anxiety and worse health outcomes.


They suggest finding possibly harmless tumours can trigger a cascade of unnecessary serious interventions with lasting consequences.


Rather than employing persuasive communications techniques to encourage people to undergo unnecessary cancer screening, some researchers writing in the journal argue more weight should be given to balanced information for patients to assist them in making informed decisions.


“Clinicians and the broader community alike want to see a reduction in the burden of cancer,” said Associate Professor Stacy Carter from the University of Sydney and a guest editor of the latest issue of the journal.


“No one wants to see a loved one or themselves endure the pain and loss that cancer can cause. It’s no surprise that members of the community and the health professions are generally supportive of early detection and treatment of cancer.”


Some cancer screening is very effective in reducing cancer burden: cervical screening and bowel cancer screening are good examples. However, evidence shows screening can lead to cancer overdiagnosis.


“Overdiagnosis is a particular problem in screening for cancers of the breast, thyroid and prostate in normal-risk adults and screening for lung cancer in smokers,” Associate Professor Carter said.


“When thinking about any screening program, policy makers need to pay attention to both the benefits and the harms produced, and weigh them against one another.”


University of Sydney researcher Dr Jolyn Hersch said public health messaging about cancer screening over many decades had largely reflected positive views held by public health organisations, professional associations, patient advocacy groups, academics and clinicians.


“Overemphasis of benefits and minimisation of harms is a common feature of many conventional communication approaches to presenting information about screening,” Dr Hersch said.


“Such communications have created highly-positive community views that screening is the ‘right’ thing to do.


“There is growing consensus that, rather than encouraging uptake, screening communication should aim primarily to inform people about harms and benefits so they can make informed decisions about participation.


“Design of effective patient decision aids may be one way to help them choose to be screened or not, depending how they personally feel about the potential benefits and harms and reduce the risk of overdiagnosis.


“Ways to better support clinicians in communicating effectively with patients about cancer screening and its benefits and harms must surely be another strategy.”


The perspectives of a cancer epidemiologist, a urologist and an oncologist on prostate cancer testing, along with an international perspective, are also published in the latest issue of the journal on the issue of PSA (prostate specific antigen) testing.


Australia has no formal prostate cancer screening program; however, PSA testing is common and in the past five years clearer guidelines for testing for men of average risk have been produced for doctors.


“Historically, there has been a lot of expert disagreement about PSA testing in Australia, Associate Professor Carter said.


“Recently, there has been greater movement towards consensus. The experts contributing to this special journal issue have some differences, but they all agree that if men are considering PSA testing, they should have an opportunity to decide with full knowledge of what it might lead to.


“Such important decisions clearly need to be given appropriate support and must be taken seriously in policymaking.”


30 July 2017.