Lowering the age of screening? A Pandora’s Box

Comments by Cancer Rose, 17/09/2023

The New USPSTF Mammography Recommendations — A Dissenting View

  • Steven Woloshin, M.D., 
  • Karsten Juhl Jørgensen, M.D., D.Med.Sci., 
  • Shelley Hwang, M.D., M.P.H., 
  • and H. Gilbert Welch, M.D., M.P.H.

De : Dartmouth Institute and Dartmouth Cancer Center, Lebanon, NH (S.W.); the Lisa Schwartz Foundation for Truth in Medicine, Norwich, VT (S.W., K.J.J., S.H., H.G.W.); Cochrane Denmark and the Center for Evidence-Based Medicine Odense, Department of Clinical Research, University of Southern Denmark, Odense (K.J.J.); the Department of Surgery, Duke University, Durham, NC (S.H.); and the Center for Surgery and Public Health, Department of Surgery, Brigham and Women’s Hospital, Boston (H.G.W.).

https://www.nejm.org/doi/full/10.1056/NEJMp2307229

September 16, 2023

The US Public Health Task Force (USPSTF) issued new recommendations for mammography screening in May 2023, advocating the start of routine mammography at age 40.
This represents a 10-year shift in the recommendations for screening, compared with the previous guidelines, which recommended breast cancer screening starting at age 50 due to the increased risks for younger populations and the limited benefits.

The decision was motivated by two arguments:
-an increase in breast cancers in younger women and
-an increase in the most aggressive cancers in black women.

We have summarized this announcement and the reactions it generated here: https://cancer-rose.fr/en/2023/05/16/lowering-the-age-for-starting-screening-but-at-what-cost/

This change in age recommendations has been widely disputed, particularly on the grounds that it will improve 'equal' treatment for the poorest social classes.
This recommendation is by no means trivial, and the price to be paid by women is likely to be very high, which is why the authors issued a warning yesterday.

Why should this concern us?

Firstly, several recent studies from this year clearly call into question the effectiveness of mammographic screening itself.
No, it doesn't 'save lives' - that myth has long been debunked - and there's no evidence that screenings in general extend lifespan.
No, mammographic screening is not responsible for a reduction in breast cancer mortality; the risk of death from breast cancer is decreasing, whether screening or not.
Breast cancer treatments are improving dramatically, so the value of primary detection is declining, which should make screening obsolete in the future.
No, mammographic screening is not harmless, the harms outweigh the benefits, and overdiagnosis is worse in current assessments.

Secondly, the American recommendations, which are highly advantageous to providers in the women's imaging sector, risk serving as an example and opening a Pandora's box that will then be impossible to close again; voices are already being raised here and there calling even for annual mammography screening...
There's nothing 'conspiracy' about this argument, In fact, breast cancer care is, it must be said publicly, a vast and profitable business, fueled by women's fear of the disease.
This cancer business is what journalist John Horgan explains at length in this article.

Thirdly, a European trial called MyPEBS, has just completed the integration of women allocated to the various study groups. 
This study, which is supposed to evaluate individualized screening based on each woman's risk of developing cancer, is clearly calibrated to encourage more and at younger age screening, as it recruits women as young as 40, and includes flagrant biases which we denounced in an open letter along with other health watchdog groups.

Women will not have to choose between screening or no screening but between a standard screening and ... more screening if they are designated “at risk”. 
However, the 'low-risk' sub-group will include very few women, and all the others will be assigned to higher-risk sub-groups very quickly, since the software, which has not been scientifically validated, admits very generous risk criteria, and women will be screened more frequently by mammography.
For example, having had a breast biopsy for even a benign lesion is a risk factor, and the number of biopsy procedures in young women for benign lesions such as fibro-adenomas has risen considerably in recent years, making many women de facto "at risk".

In short,

at a time when mammographic screening is struggling to demonstrate any relevance whatsoever, and evidence of its harmfulness is mounting, we are moving both across the Atlantic and in Europe towards more screening, in more young women, with no regard for the risks to which the population is exposed, and of course without informing them.
No one should know....

A Dissenting View

The authors state (excerpts) :

Recently, the U.S. Preventive Services Task Force (USPSTF) changed its recommendation for the starting age for mammography screening from 50 to 40 years.1
Previously, the Task Force deemed screening in 40-to-50-year-old women a personal choice. Because USPSTF recommendations are so influential, mammography screening for women in their 40s will probably become a health care performance measure; if so, it will effectively become a public health imperative with which primary care practitioners must comply. Such a change will affect more than 20 million U.S. women, and it raises some important questions.

First, is there new evidence that mortality from breast cancer is increasing? To the contrary, there has been a steady decrease in breast-cancer mortality in the United States — a major success story of modern medicine.
...
Similar patterns (of mortality reduction) are seen in other high-income countries, including both those where screening of women in their 40s is very rare (Denmark and the United Kingdom) and those where screening is rare in all age groups (Switzerland) — which suggests that the decline has resulted largely from improved treatment, not screening (see graphs).

Second, is there new evidence that the benefit of mammography is increasing? Since the previous USPSTF recommendation was made, there have been no new randomized trials of screening mammography for women in their 40s. Eight randomized trials for this age group, including the most recent (the U.K. Age trial), revealed no significant effect.2
.....
Fast-growing cancers are more likely to be missed by screening, often appearing in the interval between exams......
The USPSTF’s increasing reliance on complex statistical modeling is problematic. Estimated effects can be extremely sensitive to modeling assumptions, which often reflect the conventional wisdom at the time.
.......
So does the balance of benefits and harms support a new public health imperative? Relative risk reductions can be misleading since they contain no information about absolute risk, which is already low and steadily decreasing for this age group. To clarify the potential effects of the updated guideline in absolute terms, the table summarizes the benefits and harms.

.....
In other words, with screening, the likelihood of not dying from breast cancer in the next 10 years increases from 99.7% to 99.8%.
This effect is small, particularly in light of the potential harms and what seem to be overly optimistic assumptions of benefits. By far the most common outcomes are false alarms: the USPSTF model estimates that 36% of women 40 to 49 years of age will have at least one in a 10-year course of biennial screening.......
And some will experience fear: about a third of women describe the experience as “very scary” or “the scariest time of my life.”4....
The harms will be more frequent if screening occurs annually rather than biennially, as is the current practice for most U.S. women.
.....
Given the steadily decreasing mortality over the past 30 years attributable to improved treatments, it’s likely that fewer and fewer women will benefit from screening over time, while more screening will increase the harms.
The Task Force also argues that the new recommendation is an important first step in reducing the disparity between Black and White women in mortality from breast cancer.
....
But it’s hard to imagine how recommending the same intervention to both groups would reduce the disparity, particularly given that screening rates are already similarly high for Black and White women in their 40s......
Nor would earlier screening address the problems facing poor women, who tend to be disproportionately Black, such as the lower quality of medical services available, delayed follow-up on abnormal scans, delays to treatment, and less use of adjuvant therapy. Indeed, lowering the screening age could actually exacerbate the problems contributing to the disparity — by diverting resources toward expanded screening. We need to do more of what really works: ensure that high-quality treatment is more readily accessible to poor women with breast cancer.
.....

It would be better to allow women to make their own decisions based on their own assessment of the data and their values — and to redirect resources to ensuring that all women with breast cancer receive the best and most equitable treatment possible.

References

  1. Preventive Services Task Force. Draft recommendation statement — breast cancer: screening. May 9, 2023 (https://www.uspreventiveservicestaskforce.org/uspstf/draft-recommendation/breast-cancer-screening-adults. opens in new tab).

2. Gøtzsche PC, Jørgensen KJ. Screening for breast cancer with mammography. Cochrane Database Syst Rev 2013;2013(6):CD001877-CD001877.

3. Kramer BS, Elmore JG. Projecting the benefits and harms of mammography using statistical models: proof or proofiness? J Natl Cancer Inst 2015;107(7):djv145-djv145.

4. Schwartz LM, Woloshin S, Fowler FJ Jr, Welch HG. Enthusiasm for cancer screening in the United States. JAMA 2004;291:71-78.

5. Hayse B, Hooley RJ, Killelea BK, Horowitz NR, Chagpar AB, Lannin DR. Breast cancer biology varies by method of detection and may contribute to overdiagnosis. Surgery 2016;160:454-462.

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