In May 2024, the Canadian Task Force on Preventive Health Care issued draft guidelines on breast cancer screening for women of average and moderate risk. These guidelines are used by 60,000 family doctors and nurse practitioners in their interactions with ~8 million women aged 40-74.
Here?s how the current guidelines put women?s lives at risk:
1. The guidelines do not heed expert advice: There are no breast cancer experts on the Task Force panel and no breast cancer screening experts vote on the recommendations.
2. The guidelines ignore the importance of screening for women in their 40s: 17% of cancers occur in the 40s and are more aggressive.
3. The guidelines in the past advised against breast self-exams: Ces examens sont une mesure importante que les femmes peuvent prendre pour augmenter la détection précoce du cancer du sein, en particulier chez les femmes dont les seins sont denses.
4. Les lignes directrices exagèrent les méfaits du rappel des femmes pour des tests supplémentaires après une mammographie. Environ 10 % des femmes sont rappelées pour des images supplémentaires, ce qui peut causer de l'anxiété. Le Groupe de travail considère que cette anxiété est nuisible, et l'utilise pour dissuader les femmes de se soumettre au dépistage. Cependant, une étude démontré que cette anxiété ne dure pas longtemps, et c'est un petit prix à payer pour déterminer si le cancer est présent ou non. Mieux vaut prévenir que guérir.
5. The guidelines ignore significant health benefits of early cancer detection: Le Groupe de travail ne reconnaît pas les avantages d'éviter la chimiothérapie, la mastectomie et le lymphœdème.
6. The guidelines undervalue current data: The Task Force over values outdated and flawed studies form the 1960s to 1980s. The obsolete studies estimate that women are 15% less likely to die if they have breast screening. However, current studies show a mortality benefit of 52%.
7. The guidelines do not act on the risks of breast density: Dense breasts increase the risk of developing breast cancer and increase the risk that cancer will be masked on a mammogram. The guidelines negate the benefits of supplemental screening for women with dense breasts.
8. The guidelines do not act on the earlier incidence of breast cancer in minority women: Women of race/ethnicity other than White have earlier peak age at diagnosis, higher proportions of breast cancer diagnosed under age 50, and a peak age of death younger than White.
8. On demande aux femmes de prendre des décisions au sujet des tests de dépistage qui pourraientt leur sauver la vie en se fondant sur des renseignements inexacts. En utilisant les nouvelles lignes directrices, qui exagèrent les méfaits et sous-estiment les avantages du dépistage, les femmes peuvent prendre des décisions qui pourraient mener à un diagnostic tardif, à des souffrances inutiles et à un mauvais pronostic.
10. The guidelines ignore the rising incidence of breast cancer in young women in Canada. in the past 34 years.
11. Women aged 40?49 in jurisdictions that do not include women in the 40s in screening programs have significantly higher proportions of stages 2, 3 and 4 breast cancer compared to their peers in screener jurisdictions.
12. Mammography screening programs for women ages 40-49 in Canada are associated with significantly higher 10-year net survival for women diagnosed with breast cancer.
13.Using The OncoSim-Breast microsimulation model (Canadian Partnership Against Cancer) to simulate a cohort of 1.53 million Canadian women born in 1975 showed that compared to no screening, screening mammography is associated with an absolute mortality reduction of 4.6 (biennial 50?74), 5.9 (biennial 40?74) and 7.9 (annual 40?74) fewer deaths per 1000 women. The absolute rate of diagnosis of advanced cancers (Stage 2, 3 and 4) falls in favor of earlier stages as the number of lifetime screens increases. https://www.mdpi.com/1718-7729/30/11/686
14 Using the OncoSim model, based on 2023 treatment standards, screening a cohort of women annually for breast cancer starting at age 40 to 74 saves the Canadian health care system $459.6M over these women?s lifetime with 3499 breast cancer deaths averted and 52367 life years gained. This translates into a savings of $1880 for every woman screened (Abstract 174) https://cslide.ctimeetingtech.com/breast24hybrid/attendee/confcal_1/presentation
15 The provinces/territories have changed their policies and are not following the CTFPHC guidelines. The provinces/ territories currently including women in their screening programs starting at 40 include BC, NS, PEI, NL, NB, and YT, and those starting at age 45 are AB and NWT. There are public commitments to lower the age to 40 in SK (2025) and ON (Fall 2024). Quebec: INESSS is reviewing the evidence. Manitoba is reviewing practices.
Canadian women and their family doctors deserve to have accurate information about the benefits of screening.
