Switzerland has the highest number of MRI scanners per person in Europe. But more screening doesn’t always lead to better health outcomes, and some experts warn that early detection can sometimes do more harm than good, reports Swissinfo.ch News.
When a tsunami struck Japan in March 2011, it left 20 000 people dead and destroyed the Fukushima Daiichi nuclear power plant, triggering the worst radiation disaster since Chernobyl in 1986.
Although at lower levels than the Soviet accident 25 years prior, radioactive material was released into the environment, significantly increasing the risk to the population of developing diseases such as thyroid cancer, which proliferated among children living in and around the Ukrainian city, which was then part of the Soviet Union.
Under pressure from parents, the Fukushima prefecture ordered mandatory ultrasound examinations for everyone aged 18 or under, at the time of the accident – some 380 000 people. To date, 350 cases of thyroid cancer have been detected through these screenings which have been carried out every two years since the disaster.
The incidence of cancer was 10-12 times higher than that found in other prefectures and was initially blamed on exposure to radiation.
However, some experts have suggested that the excessive number of cases may be due to a combination of mass screening and the use of highly sensitive ultrasound equipment, which detected thyroid cancer at a very early stage that may not have progressed or found benign tumours that are commonly found in adults who die of other causes.
“Many unnecessary medical tests and treatments (and surgery) are being performed, which is resulting in psychological, financial and social burdens,” said Sanae Midorikawa, a Professor of Clinical Medicine at the Miyagi Gakuin Women’s University, 90km away from Fukushima and one of the lead physicians examining young people in the region for thyroid cancer.
But she and her colleagues came to realise that while the youngsters may have been diagnosed correctly, they would never develop symptoms, let alone die from the disease.
Scanning devices and over-diagnosis
Over-diagnosis, the treatment of a disease that won’t progress to cause symptoms, stems from a well-meaning intention: to detect illness early and save lives.
“But our assumption that catching things early will always help hasn’t proven to be correct over time,” said Suzanne O’Sullivan, a consultant neurologist at University College London and a critic of the tendency to treat normal health variations or minor problems as diseases requiring intervention.
The proliferation of ever more powerful scanning devices might combat under-diagnosis, the failure to diagnose a disease, but it’s also fuelling over-diagnosis.
Imaging for lower back pain and headaches, cancer screening and electrocardiography in low-risk populations are processes that can easily lead to this phenomenon, according to a 2017 OECD report on wasteful spending in health services that’s further supported by research published in a working paper written for the Paris-based organisation in 2025.
Switzerland, home to the world’s biggest diagnostics company, Roche, and a leading manufacturer of medical equipment, is the fourth-biggest spender on healthcare as a percentage of GDP among 33 countries comprising the EU, Turkey, the UK and the four members of the European Free Trade Association, according to the trade association Medtech Europe.
The country has the highest number of imaging devices per person among the 25 European members of the OECD, according to the Swiss federal audit office on the appropriate usage of medical imagery. There are 80 CT scanners and MRI devices per million citizens, nearly double the number for The Netherlands, although the two countries are similar in terms of life expectancy and quality of the healthcare systems.
Switzerland is also the biggest spender on in vitro diagnostics, medical tests performed on samples such as blood and urine. Although this is partly due to the cost of living, high spending on health and the quality of public health services, such as the speed at which a patient is taken into care, are also key factors, the Swiss Association of the Diagnostics Industry reports.
Yet despite heavier spending on diagnostics in wealthy nations, which leads to earlier and more frequent cancer detection, death rates from the disease remain similar to those in low-income countries, according to a 2017 New England Journal of Medicine paper cited in O’Sullivan’s book, The Age of Diagnosis, published this year.
This is because we treat cancers that aren’t necessarily going to become fatal. “We’re very good at finding diseases, but not very good at finding which will progress and which won’t,” O’Sullivan said.
Illness vs disease
It can be particularly troubling to diagnose patients without symptoms for conditions that have no cure, like Alzheimer’s disease.
Giovanni Frisoni, head of the Geneva University Hospital (HUG) Memory Centre and a Professor of Clinical Neuroscience at the University of Geneva, is part of a group which produced diagnostic criteria to to limit over-diagnosis of this neurodegenerative condition.
The dominant school of thought in neuroscience posits that the presence of certain biomarkers, like tau and amyloid, is sufficient to diagnose Alzheimer’s. Frisoni and his team, however, believe that other symptoms, such as memory loss, need to be observed before coming to a definitive conclusion.
“What really matters for patients isn’t the disease but the illness,” said Frisoni, pointing to the importance of distinguishing between two phases of a condition. In the disease phase of Alzheimer’s, for example, biomarkers can be visible for 10 to 15 years before clinical signs emerge. Then, in the illness phase – which has roughly the same duration – observable symptoms such as memory loss appear alongside biomarkers.
Some patients will never progress to the illness phase even though the disease is present.
“If you’re 80-years-old and have a bit of amyloid, chances are, you’ll die of something other than Alzheimer’s,” said Frisoni. It isn’t helpful to tell patients with biomarkers typically linked to the condition that they have the neurodegenerative disease, he said. Instead, they should be told that they are at risk of developing it.
“It’s like cardiovascular diseases,” he added. “If you have high blood pressure, it doesn’t necessarily mean you’ll have a stroke, but you are at a higher risk of having one.”
His prevention protocol for high-risk patients who have yet to show memory loss include cognitive training, physical activity, networking, cardiovascular monitoring and personalised nutritional advice. All of these activities have been shown to prevent the onset of memory loss.
Preventive screening
Preventive screening aims to detect diseases at their earliest stage, before symptoms appear or the condition progresses, enabling earlier intervention to prevent worsening or life-threatening outcomes. However, treating someone for a condition that may never cause harm can itself lead to unnecessary health risks or a deterioration in health, experts say.
For example, a prostate-specific antigen (PSA) blood test may return a positive result for prostate cancer, but the test has a high false-positive rate and most low-grade prostate cancers grow too slowly to ever cause symptoms. Yet confirming a diagnosis through physical examination is fraught with challenges.
MRI scans are often inconclusive and surgical removal of the suspected tissue can lead to infections, incontinence or impotence.
In a recent study on the incidence of prostate cancer across 26 European countries, the International Agency for Research on Cancer found that PSA tests often leads to over-diagnosis and overtreatment. While increased testing detected far more cancers in some countries (in some cases over 20 times more), overall death rates remained similar.
The authors linked this discrepancy to the screening of patients who had no symptoms, concluding that many detected cases would never have become fatal or required treatment.
For some medical conditions, preventive screening makes no difference to the outcome.
“Screening aims to improve the prognosis, but for some diseases, it doesn’t actually have any beneficial effects; it allows early diagnosis but doesn’t improve the prognosis,” says Arnaud Chiolero, epidemiologist and Professor of Population Health at the University of Fribourg and adjunct professor at the School of Global and Population Health at McGill University in Canada.
Taking cancer as an example, Chiolero says it’s important to distinguish between various types. While screening works well for colon, breast, cervical, and colorectal cancers, it has proved not to be beneficial for ovarian or thyroid cancer, and patients would have had similar outcomes had they started treatment only once symptoms appeared.
“I’m a public health doctor, and I would be glad to say that screening is always great, but it’s so much more complex than that: only some screening (for certain types of cancer) is beneficial,” he said.
Swissinfo.ch news article – When diagnosing a disease does more harm than good (Open access)
See more from MedicalBrief archives:
DIY health screening industry ‘built on fear’, Lancet warns
Prostate cancer ‘over-diagnosed’ across Europe – global experts
Little benefit from frequent monitoring of post-Tx prostate cancer
A prognostic Alzheimer’s disease blood test in the symptom-free stage — 6-year study