Cancer Screening: Does Over-Diagnosis Do More Harm than Good?

Cancer screening programs have undoubtedly improved medical treatment in modern times. However, according to a national Australian survey only 10% of Australian adults had been told of the risk of over-diagnosis in cancer screening.
Professor Glenn Salkeld, Head of the University's School of Public Health, says that people need to be given adequate, reliable information which explains the benefits and risks of screening.
"All people should be given the chance to make an informed choice about screening. We need to empower citizens to make good decisions for themselves.”
Medical experts in Australia are divided over the benefits of cancer screening - are we saving lives or harming lives?
"The evidence is clear, early detection improves survival from cancer and screening (together with improved treatments) has reduced deaths from cancer," says Warwick Lee, Adjunct Professor Medical Radiation Sciences, University of Sydney.
"Early detection of breast cancer results in diagnosis of more cancers at an early stage and with an improved chance of cure. In the example of mammographic screening, it detects early cancer and reduces the mortality from breast cancer by 20%.”
"Screening programs are important as at present it is not possible to reliably distinguish over-diagnosed cancers from lethal cancers".
Other medical experts argue that widespread screening, such as for breast and prostate cancer, can lead to healthy people being unnecessarily alarmed, falsely diagnosed, or subjected to invasive procedures that cause emotional and physical harm.
"Whenever we screen for breast, prostate, thyroid or lung cancer, there is the potential for over-diagnosis and over-treatment. These are the major downsides of screening for these cancers," says Alexandra Barratt, Professor of Public Health, University of Sydney.
To help unravel this issue, industry experts, medical professionals, researchers, and those affected by cancer will share their stories and expertise at a public forum tonight,  Wednesday 29 July, 6.30pm at University of Sydney.
One of the key issues in this debate is over-diagnosis - the detection of cancers by screening that would not otherwise have caused symptoms during a person's life. Over-diagnosis also increases the probability of over-investigation and over-treatment.
Panel members:

• 
  Glenn Salkeld, Professor of Public Health, Head and Associate Dean, Sydney School of Public Health, health economist, University of Sydney


• 
  Alexandra Barratt, Professor of Public Health, cancer screening expert, University of Sydney


• 
  Warwick Lee, Adjunct Professor Medical Radiation Sciences, radiologist, BreastScreen NSW, University of Sydney


• 
  Dr Liz Marles, general practitioner, former President of Royal Australian College of General Practitioners, Director of the Hornsby-Brooklyn GP Unit


• 
  Roberta Higginson, breast cancer survivor, recent Chair Breast Cancer Action Group NSW, member of Cancer Voices NSW Executive Committee

Event details:

• 
  What: Cancer screening: Are we harming the healthy?


• 
  When: Wednesday 29 July, 6.30 - 8pm


• 
  Where: Law School Foyer, Sydney Law School, University of Sydney


• 
  Cost: Free and open to all with online registration required


• 
  Registration: http://sydney.edu.au/sydney_ideas
  

Fast facts:

• Screening programs aim to detect very early cancers in healthy individuals who do not have symptoms.


• National screening programs are available in Australia to detect breast cancer, bowel cancer and cervical cancer. These programs are available free of charge to people for whom there is evidence that the screening test can find a cancer at a stage when treatment is more effective.


• A screening test cannot diagnose cancer - to make a cancer diagnosis, further investigations are necessary to confirm the findings of a screening test.


• Genetic screening tests are available for people with a family history of bowel, breast or skin cancers.


• Tests carry a risk of a 'false negative' or a 'false positive' result. Every test carries a small risk of 'over-diagnosis, which refers to the diagnosis of disease that will never cause symptoms or death during a person's lifetime.


• 1 in 2 Australian men and 1 in 3 Australian women will be diagnosed with cancer by the age of 85.


• Cancer is a leading cause of death in Australia - more than 43,000 people died from cancer in 2012. Cancer accounted for about 3 in 10 deaths in Australia.


• An estimated 128,000 new cases of cancer will be diagnosed in Australia this year, with that number set to rise to 150,000 by 2020.


• The most common cancers in Australia (excluding non-melanoma skin cancer) are prostate, colorectal (bowel), breast, melanoma and lung cancer. These five cancers account for over 60% of all cancers diagnosed in Australia


• Cancer costs more than $4.5 billion in direct health system costs (6.9%).

If you are in the area it is a great opportunity to hear all sides of the debate and the possible solutions for addressing the problems facing medical practitioners and patients alike.