AN “obsession with early detection” has created a “public health crisis” of almost 30 000 cancers overdiagnosed in Australia each year, says one expert in response to research published by the MJA.

Researchers analysed changes in absolute lifetime risk in five cancers – prostate, breast, renal, thyroid and melanoma – over the 30 years to 2012. After adjusting for competing risk of death and changes in risk factors, such as body mass index, the researchers estimated that, for women, 22% of breast cancers (invasive cancers, 13%), 58% of renal cancers, 73% of thyroid cancers and 54% of melanomas (invasive melanoma, 15%) were overdiagnosed.

Among men, they estimated that 42% of prostate cancers, 42% of renal cancers, 73% of thyroid cancers and 58% of melanomas (invasive melanomas, 22%) were overdiagnosed.

While acknowledging that there was some uncertainty around these estimates, the researchers noted that this equated to about 11 000 cancers in women and 18 000 cancers in men being overdiagnosed each year.

Dr Ray Moynihan, Assistant Professor and National Health and Medical Research Council Early Career Fellow at Bond University’s Institute for Evidence-Based Healthcare said this first national estimate of the extent of cancer overdiagnosis in Australia highlighted a “public health crisis”.

“When you see the figure of over 29 000 human beings going through that unnecessary anxiety, all the treatments that carry side effects, of course, all the cost, all the waste, all the opportunity cost, this is arguably a public health crisis,” he said.

Dr Moynihan, who has co-authored an article published in the BMJ on the complex drivers and possible solutions to overdiagnosis, said a key barrier in addressing this problem was a deep, cultural obsession with early detection.

“We have all become so obsessed with early detection that we have failed to recognise its downside,” Dr Moynihan told InSight+. “And I think that this is a major wake-up call that says early detection is a double-edged sword.”

Lead researcher Professor Paul Glasziou, Director of the Institute for Evidence Based Healthcare, said there would always be some unavoidable overdiagnosis in health care, but greater efforts were needed to reduce the potential harms.

“We can’t reduce the overdiagnosis to zero,” Professor Glasziou told InSight+. “But you can enforce guidelines and policies that will minimise it.”

For example, he said, some overdiagnosis was inevitable when screening women aged 50–70 years for breast cancer, but the likelihood of overdiagnosis increased when women were screened beyond age 70.

“You will detect more of these slow growing, or non-growing, cancers that won’t declare themselves in a woman’s lifetime,” he said. “So, it’s important to keep within the appropriate target age ranges in screening.”

Renal and thyroid cancers presented a greater challenge, Professor Glasziou said, because they were not screening-detected cancers.

“They are what we call ‘incidentalomas’ – cancers that are incidentally detected when you are looking for something else. For example, with renal cancer, it may be detected when you are doing an abdominal computed tomography for another reason for abdominal pain,” Professor Glasziou said.

“Again, you can’t completely avoid it, but it may be that when a sonographer is doing an ultrasound on the carotid artery, they don’t look at the thyroid unless asked to.”

In late 2018, Australia announced an alliance of clinical, consumer, research and public organisations to address overdiagnosis, and international experts met in Sydney in December 2019 to discuss strategies to wind back the associated harms (here and here).

Professor Sanchia Aranda, CEO of Cancer Council Australia, said finding practical solutions to overdiagnosis would be a significant challenge.

“This is a robust piece of analysis based on best available data and it’s true that some cancers that are diagnosed might not go on to be life threatening. And the more we refine our ability to diagnose [cancers], the more that occurs,” she said.

“The real problem, though, is we don’t have any mechanism of [identifying] at the point of diagnosis which of those cancers are the overdiagnosed ones. We can only do that when someone dies of another cause and their cancer didn’t kill them.”

Professor Aranda added that not all harms were equal.

“Not diagnosing a cancer that might have become problematic and then causes the woman’s death, would be considered a bigger harm by most women than the harm of getting a diagnosis of something that is pretty easily cured,” she said.

The MJA authors concluded that the rates of avoidable overdiagnosis need to be “reduced to the lowest level compatible with targeted screening and appropriate investigation”. Also, they wrote, there was a need to examine strategies for reducing overtreatment of low risk prostate, breast and thyroid cancers.

Professor Aranda said of the cancers studied, breast cancer was the only cancer for which Australia had an approved national screening program.

“There is always the challenge of balancing harms, benefits, cost effectiveness and clinical effectiveness. Breast cancer has an approved national screening program where the benefits of screening are known and have been analysed to outweigh the harms; so even though we know overdiagnosis occurs, we also know that participation in screening has a mortality benefit for the women who participate,” she said.

Professor Aranda pointed to UK-funded efforts that were seeking to identify molecular markers to detect cancers that would require treatment.

Active surveillance was also playing an increasingly important role, she said, particularly in prostate cancer.

“We know we are overdiagnosing prostate cancer; if you biopsied the prostates of men in their 90s, they will pretty much all have some level of prostate cancer,” she said, adding that the prostate-specific antigen (PSA) test was a “pretty difficult test because it is not prostate-cancer specific”.

Professor Aranda said about 60% of men who had been diagnosed with very early, low risk cancers were undergoing active surveillance.

“That number is increasing over time as doctors get more confident in providing this advice,” she said.

Professor Aranda agreed that managing issues with incidentally detected cancers was a significant challenge. She said it may be necessary to “shift our thinking” on how we communicate with patients about these cancers.

“Patients need to be given the information that a [lesion] might become problematic, and that progression needs to be thought of as the marker for whether intervention is needed, not necessarily the presence of a lesion,” she said.

Professor Glasziou said it was crucial not to dilute the important public health message to see a doctor about any potential cancer symptoms, such as changing moles, breast lumps or bowel bleeding. There was however also a need for greater community awareness of the variability of cancer, he said.

“The community does need to be aware that cancer is a very variable disease and some of it is very quickly deadly, some is slowly deadly and some is never deadly,” he said, adding that moves to relabel some very low risk cancers could also be a helpful step in reducing overdiagnosis.

Also, he said, risks of potential overdiagnosis needed to be considered as ever more sensitive diagnostic tests became available.

“We need to watch out for what new things we are going to end up diagnosing in time and be aware of [the potential for overdiagnosis],” he said. “It’s much harder to wind it back, once you have started doing it.”

Asked to comment on the findings, a spokesperson for the federal Minister for Health Greg Hunt said: “Cancer Australia had developed a position statement on Overdiagnosis from mammographic screening, which finds:

  • “a majority of breast cancers found through screening would progress and become symptomatic within a woman’s lifetime if left untreated;
  • research is needed, including molecular and genomic research, to find means of identifying cancers that would be of minimal risk of progression and therefore could be managed more conservatively”.

“Information about the benefits of screening as well as the risks, including overdiagnosis, assists consumers to make informed decisions about screening participation,” they said.

They said the Population Based Screening Framework – a joint publication of the Australian and state and territory governments – recognised the risk of overdiagnosis as one of the harms that could arise from participation in population screening programs.

“The Framework identifies the need for a strong evidence base on the safety, reproducibility and accuracy of screening tests and the efficacy of treatment and that the benefits of screening outweigh the harms of screening. For example, there is as yet no sufficiently accurate test to support a population screening program for prostate cancer, so the risk of overdiagnosis significantly outweighs the benefits of early detection.”


We are overinvestigating and overtreating some cancers
  • Strongly agree (47%, 60 Votes)
  • Agree (23%, 29 Votes)
  • Disagree (14%, 18 Votes)
  • Neutral (9%, 12 Votes)
  • Strongly disagree (7%, 9 Votes)

Total Voters: 128

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15 thoughts on “Overdiagnosis: 30 000 cancers from “obsession with early detection”

  1. Dr Barbara Maddock (retired GP) says:

    Regarding PSA testing. Recent study showing that a upper normal range result in relatively young men , can’t remember , maybe under 50, may need to be followed with 2 yearly testing , but if normal or low, no further testing needed as risk is so low. This would be better use of the test.

  2. Meiri Robertson says:

    The Harding Centre for health literacy provides excellent insight into this topic.
    They have created patient friendly “Fact Boxes” that can be shared with patients
    The Icon Array visualizing of the data is particularly helpful to demonstrate that we unfortunately do harm when we try to do good (often at great cost).
    All material is referenced

  3. Kate Schilling says:

    Is is very unclear from this article what they actually mean by “overdiagnosis”, the term is not defined. It is up to anybodies imagination to read it as misdiagnosis, inaccurate diagnosis?

  4. Micheal Hooper says:

    I agree with Dr David De Leacy that there is an imperative to have balanced reporting on this complex issue without emotive terms such as ‘overdiagnosis’. Unfortunately, the manner of the reporting masks the actual data and the opportunity to have a carefully thought-out rational discussion may have been lost. The real issue is not overdiagnosis but best management based on the best available evidence once the correct diagnosis is made.

  5. Anonymous says:

    INVASIVE melanoma? overdiagnosed?
    I call bullshit on that one.

  6. michael Giltrap says:

    The Federal government finances the Faecal Occult Blood screening program.
    Is anyone suggesting that positive results should not be acted upon.
    Should an obvious dysplastic polyp not be snared?
    Is a bowel cancer to be watched until it becomes stenotic or metastatic.

    The Lawyers will enjoy the flawed logic. I am not sure that my Insurer will.

  7. Hamish Foster FRACS says:

    This paper is very likely to be dangerously misinterpreted and may lead to delayed presentation of patients with aggressive cancers which should have been cured, had their cancer been detected early.

    As our knowledge of the biology of each person’s individual cancer increases, practitioners are increasingly able to design treatment appropriate for the stage and behaviour/biology of the patient’s particular cancer and circumstances. Observation is always an option.

    Early diagnosis remains a ‘gold standard’ in effective cancer management; a worthy aim, allowing appropriate treatment , certainly not a’health crisis’. No diagnosis equals ignorance.

  8. A/Prof Lilon Bandler says:

    n=1 is not evidence for screening.

    The PSA is a deeply flawed test FOR SCREENING. It has its place elsewhere.

    Similarly, “anonymous” is absolutely right: a single story about “how lucky” (even twenty stories), do not justify us spending millions of dollars of an already over-stretched health budget. We need good population health data and analysis.

    We know that “incidental findings” on unnecessary tests lead to further over-investigation and associated harms. See work by Iona Heath in UK: and Professor Stacy Carter (Australian Centre for Health Engagement, Evidence and Values) here in Australia.

  9. William Lees says:

    The poll is simplistic separate overdiagnosis and over treatment The option in prostate is don’t screen Think you’ll have difficulty convincing the 40 50 and 60 year olds diagnosed and managed with aggressive prostate cancer Are they simply meant to be collateral damage to reduce our interventions?

  10. Ian Hargreaves says:

    It all comes back to informed consent. In every single case, the doctor is required to provide the patient with all the information the patient needs to make his own decision about his treatment.

    That includes the natural history of the disease, the risks of untreated disease and the risks of treatment. The doctor also needs to discuss issues such as whether the patient can get life insurance, disability or even travel insurance when they have untreated cancer, versus having had cancer treated successfully. As a self-employed doctor, my decision to decline/request active treatment of an indolent cancer would be heavily influenced by whether I can maintain my insurance cover for my business.

    In 1990, having compulsory serology for Hep B and C to work in the UK NHS, I asked for an HIV test while they were going to take blood. The horrified Occ. Health nurse called in the pathologist, who explained that (at the time) if you had an HIV test, you could not get life insurance in the UK – irrespective of the result, having the test meant you were at higher risk. I wonder if the authors of these studies have checked with insurers on the risks of untreated vs treated cancer for premium loading/ availability of insurance?

    Back in the 1980s, in my orthopaedic training we often saw breast, thyroid, prostate and kidney cancer presenting with pathological fractures, before the primary was diagnosed. As the first comment on this article says, we do not necessarily want to go back to the days when your initial cancer presentation was the pathological fracture.

  11. Anonymous says:

    1 These days we tend to practice Defensive Medicine because the lawyers are not far away.One can be damned if he /she does and be damned if he/she doesn’t .
    2 People need a good constitution to be told they have an early tumour which can be watched . Does work in some cases of prostate cancer but I’ve never seen anyone with an in situ breast cancer who did not request surgery .
    3 I’d be interested to see the figures on the Melanoma as stated . I’ve had many many years experience with these tumours and as all know an invasive melanoma is a very deadly malignancy . I could not imagine watching an early melanocytic lesion
    4Never forget that a lot of these Researchers have limited Medical Knowledge

  12. Anonymous says:

    My dad is a retired GP. He didn’t have any symptoms of cancer but, when he had an infection, his GP thankfully sent him for a precautionary scan which found a cancer on his kidney. Again fortunately, he had private health insurance and promptly had surgery to remove the affected kidney. Pathology revealed it to be a Grade 3 cancer – but only in Stage 1. Thankfully, because my dad had a good GP in regional Australia (Cooma), we will have him around for a while longer. But I also work in the Department of Health and I am ever cognisant of the need to ensure limited funding is prioritised to where it can be most effective. It’s a difficult and complex issue, but I suspect as our knowledge of cancers improves through our investment in cancer research, we will have better ways of diagnosing and treating cancers in the near future.

  13. CC says:

    Try telling that to patients who sue because their cancer wasn’t diagnosed early.

  14. Diane Moller says:

    Is there any research on the psychological impact of having a cancer diagnosis but NOT taking any action?

  15. Dr David De Leacy FRCPA says:

    Please provide balanced reporting on this complex issue. PSA testing guidelines were actively relaxed a few years ago in the USA because of the lack specificity of the test. Guess what, metastatic prostate cancer is again on the rise. Simplistic emotive reporting around the huge complexity involved in defining a cancer grade and it’s associated treatment pathway is just dumb and wrong. The advent of the increased sensitivity and variable specificity of new genomic test modalities analysed in conjunction with other test results are actively being evaluated using AI to help provide more accurate and precise data for treatment options. “A little learning is a dangerous thing” A. Pope, 18th century.

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