May 15, 2023, by Cancer Rose
As reported by the Globe and Mail and numerous other North American media outlets in early May 2023, a proposed update to the guidelines of the USPSTF, the U.S. Preventive Services Task Force, would recommend that women at average risk for breast cancer receive screening mammograms every two years beginning at age 40.
The news has caused quite a stir because it lowers screening recommendations by 10 years from the previous screening guidelines, which called for breast cancer screening at age 50 only due to increased risks for younger populations and too little benefit.
This is a significant change.
According to USPSTF Past President Dr. Carol Mangione, "things have changed": breast cancer rates in young women have increased, advances in digital mammography have improved their detection accuracy, and better treatments result in improved survival.
At this point, we already note two statements that should raise the question of the relevance of screening:
- If the number of cancers in young women is increasing, isn't it time to investigate the causes and identify the elements that contribute to this "rejuvenation" of breast cancers?
- It is the advancement of treatment improvements that have raised breast cancer survival, and the impact of screening in this improvement of survival is now becoming increasingly doubtful, which is further inflated by the over-diagnosis that screening causes. Why advocate it then?
Explanation here: https://cancer-rose.fr/en/2021/03/26/what-is-survival/
Not surprisingly, "The American Cancer Society (ACS) applauds the return of the USPSTF recommendations to begin screening at age 40" in a press release. Companies providing imaging services to women, such as Hologic and iCAD, saw their stock prices skyrocket due to the announcement, as volumes of screening mammograms will significantly increase.
And by the way, why not recommend that women be screened by mammography starting at age 40 AND annually, and even throughout their lives without the recommended stop at age 74, so no upper limit?
This is a step blithely taken by the American Cancer Society "because age should not be a determining factor for stopping screening, but rather general health ..." as stated by Stamatia V. Destounis, MD, chair of the ACR (American College of Radiology) Breast Commission and a member of the North American Society of Radiology Public Information Advisors Network.
(For Ms. Destounis's conflicts of interest with imaging industrialist iCAD, see here: https://www.rsna.org/-/media/Files/RSNA/Annual%20meeting/2022-AMPPC-Planners-Disclosure).
JUSTIFICATION AND CONSEQUENCES OF THIS CHANGE
Judith Garber, a science journalist and policy analyst at the Lown Institute, in one article, and John Horgan, also a science writer, in another article, both try to analyze the reasons given by the American agency, which are essentially twofold:
-increase in breast cancers in younger women, and
-an increase in the most aggressive cancers in black women.
Judith Garber correctly notes that "the change in USPSTF guidelines came as a surprise to many health experts, as there have been no new clinical trials on breast cancer screening that would warrant adjusting the guidelines."
A-screening could shorten more lives than it "saves."
"The task force," Horgan explains, "justifies its decision by citing the recent increase in breast cancer among women in their 40s and the higher-than-average mortality rates among black women.
This makes no sense because mammograms do not help women live longer - according to the task force itself! Mammography has been shown to shorten more lives than it saves," according to this review* cited by Horgan, published in 2021.
In any case, both Garber and Horgan explain that even adjusting the predictive models to account for higher cancer rates in young women, the benefit-risk balance is still not much different from the previous USPSTF findings in 2016, with the harms still outweighing the expected benefit.
* "Examining the trend in all-cause mortality reveals that the trade-off between the harms and benefits of mammography has shifted toward the harms over time."
"Change always happens over time as the evidence evolves," says Ruth Etzioni, a biostatistician working at the Fred Hutchinson Cancer Center in the STAT media.
"At the same time, there has to be a compelling reason, and in the literature here, I don't see a compelling reason yet. When I looked at the 2016 modeling studies, the benefit-risk analysis was very similar."
B-The excess of aggressive cancers in black women
"The USPSTF also wanted to emphasize that black women are diagnosed with breast cancer at a more advanced stage and face a higher breast cancer mortality rate than other racial groups," J.Garber resumes; "therefore, an earlier screening start date for these patients could save lives and reduce racial disparities in breast cancer outcomes. However, although the USPSTF has used new models exploring the benefits and risks of screening for black women, it has refrained from recommending earlier screening for black women in particular."
For Ms. Garber:
-lowering the age will not solve the problem of access to care for certain populations.
- lowering the screening age is not enough to reduce racial disparities. Disparities in breast cancer mortality in the U.S. are often the result of structural, social, and economic disparities, with less opportunity for access to care for black populations.
C-benefit on mortality, but what is the trade-off?
The U.S. agency claims that the benefits of mammography, which ideally detects cancer at an early stage when it is easier to treat, outweigh the harms (i.e., false positives and over-diagnosis). But these alleged benefits of screening, which are highly hypothetical and increasingly questioned, only appear in studies that measure breast cancer mortality, and they do not consider the harms associated with overdiagnosis. They do not consider radiation-induced secondary cancers following radiotherapy (secondary bronchial cancers, leukemia), heart disease, which is significantly increased in cancer survivors, suicides, anxiety-depression syndromes, etc.
"For these reasons," Horgan writes, "researchers are increasingly focusing on 'all-cause mortality,' i.e., death from any cause, as a measure of the effectiveness of screening. Death is a strict criterion, leaving no subjective room for maneuvering. Various studies have shown that mammography does not prolong life when all-cause mortality is measured. For this reason, some experts advocate abandoning mammography screening."
J.Horgan cites Amanda Kowalski, a healthcare economist, who presents this data in "Mammograms and Mortality: How Has the Evidence Evolved?" published in the Journal of Economic Perspectives in 2021.
"Over 20 years, women who were screened died at a significantly higher rate than women in the control group," she says. Kowalski notes that screened women had an elevated risk of dying from lung and esophageal cancer; she cites evidence that radiation therapy for breast cancer increases patients' risk of fatal lung and esophageal cancer."
Here's J.Horgan's caveat: "Mammograms may benefit women with above-average breast cancer risk, such as those whose family members have succumbed to the disease. But Professor Kowalski's findings have a devastating consequence: screening healthy, asymptomatic women ends up killing more women than it saves."
This corroborates M. Baum's findings in a 2013 BMJ publication that the harms of breast cancer screening outweigh its benefits if deaths from treatment are considered.
SCENARIOS
The USPSTF's modeling report for its new recommendations presents many scenarios that estimate the rates at which breast cancer screening would result in certain benefits and harms at different ages of onset, duration, and to varying screening rates.
But in every case, a person with no particular excess risk who gets screened is more likely to be treated for cancer that would never have hurt her than to avoid dying from breast cancer. She is more than twice as likely to die of breast cancer anyway, says J.Garber, than to have aggressive cancer detected and successfully treated. And screened women are far more likely to undergo a biopsy unnecessarily or receive a false-positive result than to avoid dying from breast cancer.
It's all about the trade-offs: increasing screening, starting it earlier, and continuing it later, may prevent deaths, but at the cost of how many false positives, over-diagnosis, and over-treatment, which in turn compromise health and survival?
What are the compromises we accept? Is every individual willing to accept the same trade-off as their neighbor?
A decision made in the interest of population health may not be acceptable to every individual. What price is each woman willing to pay for a death from breast cancer to be prevented, knowing that at the same time, other women (including herself) may experience the detection of cancer that would not have been fatal, exposing her to overtreatment, to possible secondary cancer due to radiation therapy for cancer that could have been ignored?
With the lowering of the screening start age from 50 to 40, the USPSTF is effectively saying that to avoid one additional breast cancer death per 1,000 women screened, women must accept an additional 519 false positives, 62 more unnecessary biopsies and two additional cases of overdiagnosis" compared to the false positives, unnecessary biopsies, and overdiagnoses that already exist for screening starting at age 50.
This is exactly what lowering the screening start age by a decade means.
CONCLUSION, a step backward
According to Horgan, these changes in the USPSTF recommendations are not justified. For him, "the lure of profit cannot be dismissed. Breast cancer management is a vast, profitable business, fueled by women's fear of the disease." This cancer business is what he explains at length in this article.
The modeling used to concretely assess what screening will produce "still does not take into account the long-term negative implications of cancer screening (e.g., overdiagnosis) or the fact that tumors sometimes grow in unexpected ways, or the fact that tumors sometimes grow and regress at different rates," as V. Prasad, an American professor of oncology and hematology, explains in his 2021 video.
Other reactions note the very lucrative nature of this new recommendation: https://radiologybusiness.com/topics/medical-imaging/womens-imaging/uspstf-recommends-women-begin-breast-cancer-screening-40-boosting-stocks-mammo-related-firms
The Radiology business says, "The U.S. Preventive Services Task Force released new recommendations on breast cancer screening Tuesday, now urging all women to be screened every two years starting at age 40.
The draft guidelines mark a change from previous USPSTF standards, which called for screening starting at age 50. Women's imaging vendors such as Hologic and iCAD saw their stock prices soar Tuesday morning following the news, as screening volumes are expected to increase.
The influential USPSTF had previously encouraged women to "make an individual decision" about when to begin screening before age 50, but is now reversing course and aligning with guidelines set forth by medical societies."
This move, which you can bet will be adopted in other Western countries, can be viewed as a real step backward at a time when modern medicine is more about measured, weighted thought in collaboration with the patient, and when the question of de-escalation of harmful routine procedures was beginning to be asked.
Without any evidence, women's information is being put at risk once more, with the message that more screening equals saving lives.
At the same time, the Council of Europe calls for caution.
Even the American Cancer Institute encourages guideline developers (study financed by the NCI) to do more research before updating their guidelines for revision to ensure that the best possible data on the adverse effects of screening are used to make their recommendations.
We are a long way from that...