October the 20th
In 2017, we conducted a critical review of the French National Cancer Institute (INCa) information booklet for women on breast cancer screening, being sent with their first invitation.
At the time, the score for the quality of the information was not outstanding. A new 2022 edition for women is now accessible online. We will examine and compare the changes made between the two editions.
Sophie, our patient referent, compared the two booklets to assess how the INCa's communication was progressing. Below is a summary of the analysis she conducted.
The negative points
1) This booklet is only sent once, at the age of 50, for the first screening, and then at each of the subsequent screenings, a different document (a short leaflet) is provided: the leaflet does not mention any of the harms of screening. Instead, it indicates a link to a website for more information. It is obvious that, over time, the message that will remain in the minds of women will be the one in the leaflet, with none of the harms presented, which will be completely forgotten.
2) Among the benefits, a special emphasis is placed on 5-year survival, which is not an indicator for screening effectiveness.
3) The mortality reduction is presented as a relative percentage reduction (15-21%), meanwhile the overdiagnosis is presented as an absolute percentage (10-20%), which are not comparable. This flaw exists in the 2017 booklet as well.
ATTENTION: A 20% decrease in cancer mortality does not mean that 20 fewer women screened out of 100 will die of cancer. This is just an indication of relative risk. The authors disregard the request of women citizens to no longer be misled by numbers that do not mean what they appear to suggest. The 20% fewer deaths does not mean that 20 fewer women out of 100 will die of breast cancer if they are screened. The 20% reduction in deaths is only a relative risk reduction between two compared groups of women.
In fact, according to a projection made by the Cochrane Collaboration based on several studies, for every 2,000 women screened over a period of 10 years, 4 will die of breast cancer; for a group of women not screened over the same period of time, 5 will die of breast cancer; the reduction from 5 to 4 mathematically represents a 20% reduction in mortality, but in absolute terms, only one woman's death will be prevented.
Actually, this corresponds to an absolute risk reduction of 0.05% (1 woman in 2000) to 0.1% (1 woman in 1000) at the end of 10 to 25 years of screening, depending on the estimates used (American, US TaskForce, Prescrire journal). (5)
Concerning the rate of overdiagnosis, the 10 to 20% indicated corresponds to the lowest evaluation, other studies suggest much higher rates of overdiagnosis.
4) The NIH (National Cancer Institute) website is cited in the booklet's references to support the survival statistics put forward in the booklet. But it omits the page of the same institute that indicates that survival is not a good indicator of the effectiveness of screening, and it also omits the page where the rate of overdiagnosis is given as 20 to 50%. Indicating a rate at its low range is an option in a document, but the high range must also be honestly given.
What does the NIH say specifically regarding these two parameters ?
On overdiagnosis rates https://www.cancer.gov/types/breast/hp/breast-screening-pdq#_13_toc
Magnitude of Effect: Between 20% and 50% of screen-detected cancers represent overdiagnosis based on patient age, life expectancy, and tumor type (ductal carcinoma in situ and/or invasive).[11,12] These estimates are based on two imperfect analytic methods:[11,13]
Long-term follow-up of RCTs of screening.
The calculation of excess incidence in large screening programs.[11,12]
Study Design: RCTs, descriptive, population-based comparisons, autopsy series, and series of mammary reduction specimens.
On survival and screening effectiveness https://www.cancer.gov/about-cancer/screening/research/what-screening-statistics-mean
Much of the confusion surrounding the benefits of screening comes from interpreting the statistics that are often used to describe the results of screening studies. An improvement in survival—how long a person lives after a cancer diagnosis—among people who have undergone a cancer screening test is often taken to imply that the test saves lives.
But survival cannot be used accurately for this purpose because of several sources of bias.
5) The “choice of screening” is no longer mentioned in the booklet title, and the last chapter on screening options (to accept or do not accept) has been removed and replaced with testimonials on the benefits (a reassuring example of a screening that "saved" a woman's life, another of a woman who, not having been screened, might have received a more aggressive treatment)
This option of choice was included at the end of the 2017 booklet:
6) There is still no visual pictogram (as requested by women citizens), that illustrates in absolute numbers the benefits and the harms, to have a global vision and to allow the women to make their choice.
7) The harms of screening continue to be named "limitations" (page 13 of the booklet), whereas the term in English is "harms".
"Limitations" rather implies the inability to detect correctly.
8) Messages from personalities (president of INCa), authorities (recommendation in Europe), appeals to fear (if you don't get screened...), are used as influence techniques.
The positive points.
1) A specific page that groups screening harms (also present in 2017, but not grouped together and without a clear title for each harm).
2) Better organization of information on prevention (risk and protective factors, table on cancer statistics related to each risk factor, page 9)
3) Easier to read, a more visual document
4) The addition of the midwife (alternative to the general practitioner or gynecologist) in the follow-up clinical examinations and to answer questions on screening.
Comparison of the texts of the two booklets in the table
This booklet, ideally corrected to address the persistent deficiencies that Sophie identified for us, may be sent with each screening invitation, not just at age 50.
In the leaflet for successive screenings (beyond the age of 50), the harms of screening and recommendations on prevention have been omitted, resulting in abbreviated and insufficient information.
Women must now be completely and appropriately informed, as requested during the citizen consultation, and that for the rest of their lives of “screened women”.
Those women who had their initial screening before 2022 will never receive this information.
This can be implemented without too much difficulty by simply replacing the leaflet planned for the next invitations by this booklet, duly completed and corrected for its weaknesses.