The Task Force that creates the breast screening guidelines, as well as many other guidelines, is an independent body, made up of volunteers who do not have any expertise in breast cancer. The Task Force is funded by the Public Health Agency of Canada.

Role of the Task Force: It develops guidelines to support~48,000 family doctors and 6000 nurse practitioners in delivering preventive health care to Canadians. However, when it comes to breast cancer screening guidelines, we have many concerns. Many other specialties do as well. A coalition has been formed with these specialties. Coalition of Responsible Healthcare Guidelines  responsiblehealthcareguidelines.ca

The 2024 breast cancer screening recommendations are essentially unchanged from 2011 and 2018. The guidelines given to 48 000 family doctors and 6000 nurse practitioners:

• Recommend AGAINST screening at 40
• Recommend AGAINST supplemental screening for women with dense breasts
• Recommend AGAINST screening after 74
• Recommend screening only every 2-3 years for ages 50-74

These guidelines are causing harm to Canadians. We need to see change.

In May 2023, the US Task Force published draft guidelines, recommending that the screening age be lowered to 40. The Canadian government announced $500,000 to expedite an update of our breast cancer screening guidelines (June 2023).

The announcement stated, “Having breast cancer screening guidelines that are based on the latest science is essential…. Updates to Task Force guidelines ensure they remain reflective of the best and most current available evidence."

Members of the Liberal government stated that it was important to ensure that women have access to screening at 40 because more women are being diagnosed earlier and because the needs of racialized women are not being taken into consideration.

Rebuild the Task Force with fulsome input from experts in breast cancer screening and other areas of health.

The 12-member volunteer panel does not have any experts in breast cancer or breast imaging.

The 5-member breast working group includes two family doctors, a gastroenterologist, a nephrologist, and a nurse practitioner.

These non-breast cancer experts decide and vote on the guidelines.  .

There are only two patients involved in the 2024 update, and they do not vote.

Breast cancer experts, who are aware of the clinical context and changing data, should have a vote, but they are excluded from voting/decision-making.

Many Canadians assume that the guidelines are made by breast cancer experts. This is a breach of the public’s trust.

There are many errors discussed below as a result of expert input not being heeded.

Rebuild the Task Force with accountability.

The Task Force lacks accountability. It was formed in the 1970s, but disbanded in 2005. When it was resurrected in 2010, the design failed to include an internal accountability structure for oversight.

The Task Force is considered to be an arm’s length body and that while this is reasonable from a scientific point of view, accountability is needed. This is critical in ensuring that guideline errors are acknowledged and corrected in a timely fashion and that expert advice is not ignored.

The conduct of the Task Force, in terms of how members are appointed, how working groups are composed, how evidence is selected, how recommendations are made etc. requires a governance structure that makes it accountable to Canadians.

Once the guidelines are published, they remain in place ~7 years. There needs to be a process for updating the recommendations earlier as new research is published, so that they reflect current knowledge and clinical realities.

The Task Force does not monitor the outcomes of their guidelines. There have been worsening outcomes with an increase in the incidence of later-stage breast cancer since 2011 following the recommendation not to routinely screen women in the 40s.

A validated Canadian model predicts that following the Task Force recommendation of not screening Canadian women in their 40s is leading to over 460 avoidable breast cancer deaths in Canadian women each year. Recently published Canadian research also shows that there are large reductions in treatment costs when cancers are detected earlier.

Multiple other screening guidelines in cancer and non-cancer fields have similar reactions from experts and are similarly concerning. The problem is fundamental to the structure and the accountability of the Task Force.

The Public Health Agency of Canada (PHAC) was notified by physicians who testified of egregious behaviours by the Task Force leadership; yet, there were inadequate mechanisms to address these actions.

Expert advisors to the Ottawa Evidence Review Synthesis Centre (ERSC), conveyed that their expert input was put aside and that the Task Force dictated to them what evidence to consider. “The working group overrode our recommendations ...they dictated what evidence could be used. They insisted on including the Randomized Controlled Trials (RCTs) that were 40 to 60 years old. Because of that, the evidence generated for these recommendations does not reflect the most up-to-date evidence.” Since the Task Force insisted on the inclusion of now obsolete data from RCTs that did not reflect technology, treatment or outcomes of breast cancer management today, these old trials misinformed the current breast screening guideline update.         

The recommendation not to screen at 40 stands in stark contrast to the recommendations from the U.S. Task Force, the Canadian Cancer Society, NCCN, US breast cancer organizations, the Canadian Society of Breast Imaging, CAR, and the majority of Canadian provinces, all of which have recognized the need to screen at 40.

Rebuild the Task Force with full and appropriate transparency.

Expert advisors were required to sign nondisclosure agreements and irrevocably be signatories to the recommendations made by the Task Force, notwithstanding that their expert input may have been ignored or that they disagreed with the recommendations.

There was siloing of information due to the use of multiple evidence review centres in the guideline making process; each evidence review centre was unaware of the others’ work.

Task Force members promoted the inclusion of patient voices in the guideline creation process, however, the two patients had inadequate training and no vote on recommendations.

The Task Force released the draft guidelines but did not reveal or release all evidence to support their conclusions. The modelling results are not yet published.

It was not explained to the public that the Task Force used the US Task Force breast density evidence review and did not do their own evidence review in creating the guideline on supplemental screening for women with dense breasts.

The Task Force will not explain why figures for over diagnosis and the number of breast cancer cases differ significantly from the numbers in the 2018 guidelines.

Rebuild the Task Force with content expert leadership and methodologist assistance.

Content experts were members of the Working Group but they were not allowed to vote on the resolutions.

Task Force members lack the necessary expertise to evaluate the significance of evidence, the validity of data, and the most suitable analytical methods concerning the current diagnosis and treatment of relevant diseases. It is important to move beyond RCTs as the US Task Force has done, “Randomized trials include technology that is no longer representative of current practice. Observational trials allow us to be more quantitative and to use modern data to show what the possibility of mortality reduction is. Modelling will allow us to go beyond that and extrapolate from what we've learned in the randomized and observational studies.

There is a great deal of evidence on the benefits of supplemental screening for women with dense breasts and starting screening at age 40; yet, as non-experts, Task Force members diminished the value of this evidence.

Task Force “set arbitrary thresholds to assess the data and used too short an observation time to allow the full impact of the benefits to be measured. The absence of meaningful involvement by content experts resulted in errors in interpretation of data and misplaced emphasis on the weight of short-term (10-year) survival while ignoring long term survival benefit of early detection. Ten years is an inappropriate timeline to determine the benefits of early detection given the long trajectory of breast cancer where risk of recurrence continues 20-30 years after diagnosis, underlying the need for inclusion of disease experts to understand the context of the disease they are studying.

The Task Force suggestion of a 3-year screening interval for women 40-74 is without solid basis in evidence.

The Task Force omitted the benefit of early-stage diagnosis and decreased morbidity of treatment. Specifically, in their knowledge translation tool, the only benefit of early detection they considered was the decreased risk of dying of breast cancer, but not the years of life gained (highly important for younger women) or the options of avoiding mastectomy, chemotherapy, and armpit surgery that often results in lifelong swelling of the hand and arm, which women consider as huge benefits. As such, they are communicating only half the benefit of screening, but all of the potential harms.  Additionally, they assumed the mortality benefit was the same for women of all ages, despite evidence showing that women 40-49 have higher benefit.

The Task Force has a dangerous misconception that improved life expectancy is attributable to better treatment, implying that treatment is a substitute for early detection. This comes from a belief based on a lack of awareness of all the data and a strong belief that treatment can solve anything. The Task Force view is problematic.

Some members of the Task Force say that screening is less important because treatment is getting better, but it's not a contest. Screening and treatment are synergistic. Cancer can be treated more effectively and less aggressively when it's found earlier. The stage of diagnosis does matter. Some members of the Task Force claim that screening can't save the lives of women with rapidly growing cancers. That's not true. Statistics Canada has shown that when triple negative cancer is detected at stage one, the five-year survival is 96%, but at stage four, it's only 7%.

The Task Force uses an incorrect metric for early detection in their modelling: screen detected cancers are typically Stage I, therefore Stage II and beyond should be considered evidence of screening efficacy, while the Task Force uses Stage III and beyond.

A state of confusion exists for physicians and the public. The current state of multiple disparate guidelines on the same topic coming from specialty societies and the Task Force leaves family physicians and patients unsure of what screening regimen is optimal. Expertise from specialist groups should be incorporated into the guideline process so that there are clear national guidelines.

Task Force members must have the expertise to evaluate incoming evidence objectively, free from bias, ensuring that family doctors and the public receive impartial information to inform their health decisions.

Rebuild the Task Force with ethics oversight.

Oversight is required with respect to ethical conduct of the Task Force and Working Group members. During the 2023/2024 update, Task Force members made public statements voicing their opinions on screening and indicating a prejudicial stance on the recommendations, up to a year before the update process had been completed. They were not removed from influential leadership positions, despite attention being drawn to their statements. A predetermined outcome for the guidelines was evident. Before the Task Force even began its work on this guideline, the co-chair publicly stated that she didn't believe there was any new evidence and didn't think the recommendations would change.

There were strong indications of bias by Task Force members in terms of undervaluing the benefits and overstating the harms of screening.

Data is presented by the Task Force in a manner that is likely to misinform the public. Michelle Nadler, advisor to the Task Force, stated information to the public “should be accessible and shared in absolute numbers.” However, the exclusive use of absolute numbers in Task Force documents and recommendations creates false perceptions. This non-standard practice tends to minimize the large benefits associated with earlier cancer detection.  Data should be presented in both absolute and relative terms.

In 2018, the Task Force made egregious errors that have gone unchecked: They stated that there were only 7 cancers in 1000 women 40-49 in 7 years. However, in the 2024 guidelines, they state there are 19 cancers in 1000 women in 10 years. The number of cancers in women 40-49 can be derived from Statistics Canada incidence rates. By falsely stating there were fewer cancers in women 40-49 in 2018, the Task Force minimized the value of screening.

In the 2018 recommendations the Task Force ignored other data and chose to present a single inflated value of 48% for overdiagnosis (while more credible reports suggest 1-10%). This came from the Canadian National Breast Screening Study (CNBSS). The CNBSS is currently under investigation by the University of Toronto for subverted randomization. The CNBSS publication on overdiagnosis has been heavily criticized due to inconsistent data.  Furthermore, the Task Force made major methodological errors in applying the overdiagnosis estimate.

The ERSC for the 2024 guidelines used multiple trials to arrive at an estimate of overdiagnosis. They found that overdiagnosis including the discredited CNBSS trial was 11% (DCIS and invasive cancers) and 6% (invasive only).  Without the CNBSS, these numbers are 9% (DCIS and invasive) and 3% invasive.  Again, the 2018 guidelines contained an error in the value for overdiagnosis which devalued screening, The Task Force continues to use the 11% value of overdiagnosis for the 2024 guidelines which includes the CNBSS trial.

The participants in the historical RCTs (such as the flawed CNBSS) were almost entirely white women. This ignores the important issues of earlier, more aggressive cancers and poorer outcomes in racialized women, failing to consider Canada’s diverse population and introducing inequity.

The Task Force acknowledged the increased risk of breast cancer in aged 40-49 racialized women and increased mortality, but did not lower the screening age to give these women equity in the opportunity for early detection.

The Task Force continues to use a static, “one size fits all” tool which does not individualize a women’s risk to help inform her appropriately of her own personal benefit of screening. There are validated risk assessment tools, such as the IBIS tool, which could be incorporated into a personalized decision tool.

The Task Force used uneven and inconsistent thresholds of uncertain origin to create recommendations for screening. To elaborate (outside of testimony), there were 1350 cases of cervical cancer in Canadian women of all ages in one year, and 350 deaths. The Task Force recommends screening for cervical cancer. The incidence of colorectal cancer in ages 50-59 is ~ 50/100,000 and there is a clear recommendation to screen. However, the incidence of breast cancer in women 45-49 is 164/100,000 and yet there is no recommendation to screen.

Dr Nadler, advisor to the Task Force stated that “the Task Force's mandate is that women be informed…. Whatever choice they make about screening… the Task Force doesn't mind so long as the woman is informed.” To make informed choices, accurate information is required. It is unethical for the Task Force to misinform the public and physicians by providing inaccurate and manipulated data as seen in examples above and below.

Measures to audit outcomes associated with the Task Force recommendations must be implemented.

Statistics Canada data showed that following the 2011 Task Force recommendations, there was a noted ~10% increase in metastatic breast cancer both in women 40-49 and 50-59. The Task Force does not monitor the outcomes of its guidelines after they are implemented. Additionally, provincial differences in screening practices should be employed to determine downstream impacts of cancer screening. Modelling data should also be used.

If you don't screen women in their forties in Canada, we estimate this translates into 400 to 600 women's lives lost per year.

The US monitored mortality trends after recommending against prostate cancer screening in 2012, and subsequently changed its prostate cancer screening recommendations in 2018. We have no similar monitoring ongoing in Canada.

Although cost was not considered by the Task Force, a recent Canadian study shows that potential saving of $460M for each cohort of women 40-74 by avoiding the need for expensive therapies used for late-stage disease.

There are inequities across the country; where a woman lives impacts her ability to find cancer early. Currently, 6 provinces and territories screen at 40 (NS ON NB PEI YT BC). AB and NWT screen at 45. Only SK, MB, NL have committed to lowering the age in 2025/2026. QC has not yet committed. Supplemental screening for women with dense breasts is also dependent on where an individual lives.

Current science and research that should be used in creating the 2024 Breast Screening Guidelines

1. The incidence rates of breast cancer in women under the age of 50 in Canada have increased significantly. In the past 34 years, incidence rates of breast cancer in the 20s has increased by 45.5%, in the 30s by 12.5%, and in the 40s by 9.1%. This explains the importance of breast cancer in women the 40s (17% of all breast cancers diagnosed) and similar increases observed in the USA was one reason for changing the guidelines to screen women in the 40s.

 https://doi.org/10.1200/JCO.23.00348

2. 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 jurisdictions where women are included in the screening program at 40. Women in their 40s have significantly higher proportions of stage   2 and 3 breast cancer compared with those in their 50s. There has been a 10.3% increase in stage 4 breast cancer since 2011 when the Task Force guidelines were changed to not include women in the 40s. https://www.mdpi.com/1718-7729/29/8/444

3. 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. Women ages 40-49 living in provinces/territories that included women in the 40s in screening programs had a reduced breast cancer mortality and a higher net survival at 10 years compared to those living in provinces that only included women in programs starting at age 50. https://doi.org/10.1177/08465371241246422

4. The treatment costs based on stage and molecular subtype of breast cancer have risen exponentially due to the rapidly evolving breast cancer treatment. The 2023 mean costs per patient for Stages 1, 3 and 4 (incurable) breast cancer are C$ 39,263, C$ 97,668 and C$ 370,398. Breast cancers detected by screening are on average stage 1 while cancers that are found with symptoms are diagnosed at stage 2, 3 or 4. https://doi.org/10.3390/curroncol30090571

5. 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

6. 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

7. 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.

(submitted manuscript, collaboration with Stats Canada)

8. The provinces/territories have changed their policies and are not following the Task Force 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 (Jan 2025) and ON (Fall 2024). In Quebec, the INESSS is reviewing the evidence. Manitoba is the only remaining province.

9. The Evidence review team for the Task Force shows that using modern studies and observational trials, screening mammography is associated with a 40-60% reduction in breast cancer mortality, compared with the 27% reduction seen in the 40–60-year-old randomized trials.