Health screening needs independent regular re-evaluation

October 2, 2021, Dr. C. Bour

BMJ 2021 ; 374 doi : (Publié le 27 septembre 2021)


Fabienne G Ropers, consultant, Department of General Paediatrics, Willem Alexander Children's Hospital, Leiden University Medical Center, Leiden, Netherlands Alexandra Barratt, professor, Sydney School of Public Health, University of Sydney, Sydney, New South Wales, Australia

Timothy J Wilt, professor, Minneapolis VA Center for Care Delivery and Outcomes Research and the University of Minnesota, Minneapolis, MN, USA

Stuart G Nicholls, researcher, Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Canada

Sian Taylor-Phillips, professor, Warwick Medical School, Coventry, UK

Barnett S Kramer, consultant, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD, USA

Laura J Esserman, professor, Helen Diller Family Comprehensive Cancer Center, University of California San Francisco, San Francisco, CA, USA

Susan L Norris, doctor, Oregon Health and Science University, Portland, OR, USA

Lorna M Gibson, consultant, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK

Russell P Harris, emeritus professor, School of Medicine, University of North Carolina at Chapel Hill, NC, USA

Stacy M Carter, director, Australian Centre for Health Engagement, Evidence and Values, University of Wollongong, Wollongong, NSW, Australia Gemma Jacklyn, consultant, Sydney School of Public Health, University of Sydney, Sydney, New South Wales, Australia

Karsten Juhl Jørgensen, chief physician, Centre for Evidence-Based Medicine Odense (CEBMO) and Cochrane Denmark, Department of Clinical Research, University of Southern Denmark, Odense, Denmark 

According to the authors (researchers, medical professors, physicians, etc.), new circumstances that differ from the initial context in which screening programs were implemented may alter the benefit and risk profile of screening programmes

From the early beginnings of screening, intended to detect disease or risk factors before symptoms appeared, there is evidence that screening delivers health benefits but also harms and costs. It is important to note that these outcomes are not constants: they change with new evidence, vary between contexts, and over time.

Screening practices (whether organised as programmes or not) tend to be slow to react to these changes; alterations are often resisted and controversial.

According to the authors, reasons for resistance to change in established and entrenched programs include both financial interests (of individuals, groups, or lobbies with a vested interest in continued screening), attention to sunk costs,[1] and lack of evidence of high certainty or proper evaluation of existing evidence. But there is also a problematic belief that early detection is always better, and simply inertia or preference for the status quo. 

Screening programmes are often financed within finite collective healthcare budgets. They target asymptomatic people, most of whom are not those who need healthcare most. 

Therefore, continuing screening in the face of changing circumstances deserves careful consideration, as it potentially leads to harm to healthy citizens and wastes scarce resources.

While there are well-established principles for starting screening, none exist for stopping it.

As experts who have worked on screening over many years, the authors see an urgent need for clear, agreed methods for actively re-evaluating existing practices.

Why screening practices need re-evaluation

The value of screening may be changed by several factors, including changes in disease incidence, advances in diagnosis and treatment, evidence from ongoing programmes, and preventive possibilities.

For example, in some cases, so-called primary prevention, i.e., prevention before the disease occurs, may decrease disease incidence and thus the absolute benefit from screening.

New data showing that therapeutic advances contribute more than screening to the reduction of mortality by the disease are, of course, essential.

In the context of breast cancer

This article is, of course, "up to date" at the dawn of the pink October wave. Since the year 2000, early whistleblowers, epidemiologists, for the most part, have been warning about the harmful effects of breast cancer screening, of which it is imperative to inform women.

According to several reviews, the adverse effects prevail when the harmful effects attributable to screening and overtreatment are included in calculating mortality and morbidity[2].

In all cases, and according to independent evaluations, the benefit of screening is always minimal compared to the added harms it exposes. As a result, several countries have decided to inform women through decision support tools [3]. At the same time, the French communication relentlessly continues its promotion in the media with untruths, as in the magazine Dr. Good where we also learn that mammography delivers UV [4]...

Or in the show 'Envoyé Spécial' where "awareness" of screening seems to be a major concern rather than objective information.

John Horgan, an American science journalist, wrote an excellent summary of the enormous gap between reality and the almost industrial promotion of screenings and certain treatments based on distortions of scientific data.[5]

We are now well aware of the problems of over-diagnosis[6] and over-treatment that screening at any cost leads to, in the face of a non-significant reduction in mortality[7], particularly for breast cancer. It is becoming urgent to consider this modern knowledge when questioning the relevance of low-contribution screening such as that for breast cancer.

Reactions to BMJ article

1° Reaction of Pr.M.Baum

Michael Baum

Professor emeritus of surgery and visiting professor of medical humanities UCL-London

He comments:

"Their mantra, "catch it early and save a life" has led to the wastage of huge human and technical resources, delayed the introduction of more valuable public health initiatives, and harmed countless asymptomatic individuals by over-diagnosis and over-treatment. As the ultimate reductio ad absurdum, there has been a very high profile of a screening programme using liquid biopsies to identify 30 different cancers in the last week. (see this link; ). It reaches the point of farce when they claim the highest sensitivity for metastatic cancers with unknown primaries. I hate to think how much damage was done to the patient in the frantic research for the primary. I would humbly suggest that the first agenda item for this new committee would be to nip this in the bud."

We talked about liquid biopsies, which quickly showed their limits in terms of screening. Indeed, finding a circulating cell does not make the individual a cancerous person in the future. What will we do with all these "findings" in people who complain of nothing and who will have to undergo heavy and repetitive complementary explorations to find something or nothing at all one day hypothetically? [8]

If applied to cancer screening in an asymptomatic population, these circulating tumor DNA tests will have the same problems of sensitivity and specificity as traditional biomarkers, in addition to their high cost and complexity.

2. Reaction of Dr. Shyan Goh

Orthopaedic Surgeon-Sydney, Australia

Dr. Goh cites the WHO document, a guide on screening programs that we also present in our webpages [9], which can be downloaded in French for interested readers [10].

This paper on population-based screening, Dr. Goh explains, is full of examples of how a screening idea does not necessarily work the same way in an international setting.
One important premise of population-based screening is that "the benefits of screening outweigh the potential harms."

The question here is, says the author, what are the "potential harms" of screening?

Many clinicians advocate various screening programmes based on the focus upon potential harms caused by the disease being screened, often in the form of mortality rates from the disease.

Others and much of the public looked at overall mortality and morbidities of the screening programme, including deaths from the diseases as well as of other causes including complications of screening (e.g., biopsy for mammography screening in case of false alarm, Editor's note)


We conclude with Dr. Goh's pertinent question: which viewpoint is more important, that of the clinicians focused on the search for more and more cases, or that of the public more interested in overall mortality and morbidity, the one that also captures the harms of screening?

In 2021, after several decades of errors and controversies, the current data no longer show the superiority of the breast cancer screening program.

When, but when, and after how many infantilizing pink campaigns will the public authorities and health authorities finally find the courage, with the support of the media, to inform women?


[1] In behavioral economics, sunk costs are costs that have already been paid definitively; they are neither refundable nor recoverable in any other way.




Interview with Dr. Pierre-Yves Pierga "Finally, regarding exposure to UV rays, if we add up all the mammograms performed in a lifetime as part of the screening, it represents less than a CT scan. So the exposure remains reduced."

We have pointed out the error to the editors; it is indeed X-rays.






The WHO guide is the third decision support tool in the article, from the top[10],-maximize-benefits-and-minimize-harm-2020

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