Question Period Note: Canadian Task Force on Preventative Health Care's Breast Cancer Screening Guideline

• In 2018, the Canadian Task Force on Preventive Health Care (Task Force) updated its guideline on screening for breast cancer in women aged 40-74, who are not at increased risk for breast cancer. Since this guideline’s publication, some advocacy groups, including medical imaging professionals and researchers, have publicly contested various aspects of the guideline.
• The Task Force announced in June 2023 that it was undertaking an expedited update of the 2018 guideline. Due to the complexity and amount of evidence being assessed, a publication date of spring 2024 is being targeted.
• On April 30, 2024, the United States Preventive Services Task Force issued the final version of their recommendation on breast cancer screening, which includes lowering the age of screening initiation from 50 to 40. It is anticipated that the release of this final guideline will generate stakeholder and media interest.

• We recognize that breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer death for women in Canada.
• We are supportive of the Canadian Task Force on Preventive Health Care’s update of its breast cancer screening guideline on an expedited basis using the best available scientific evidence and considerations, including patients’ values and preferences.
• In December 2023, the Public Health Agency of Canada published the What We Heard Report from its knowledge exchange event on breast cancer screening which took place on September 26 and 27, 2023.
IF PRESSED ON THE REVISION TO THE TIMELINE FOR THE TASK FORCE’S GUIDELINE UPDATE:

• We are supportive of the Task Force’s efforts and appreciate that more time is necessary to undertake a comprehensive review given the volume and complexity of the evidence.
• The Public Health Agency of Canada is in regular contact with the Task Force concerning the status of the breast cancer screening guideline, and will continue to work with the Task Force to ensure the outcome is rigorous, evidence-based, and in the best interest of women and all persons living in Canada.
IF PRESSED ON THE ROLE OF THE CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE:

• The Government of Canada provides funding to the Canadian Task Force on Preventive Health Care, an arms-length body of up to 15 individuals with experience in primary care, public health, preventive medicine and guideline methodology.
• Task Force guidelines are established by using a rigorous review of available scientific evidence and research and applying a gold standard approach for the establishment of guidelines.
• PHAC ensures rigorous and appropriate methods are used to analyze the scientific evidence that form the basis of the recommendations made by the Task Force.
IF PRESSED ON WHY THE GOVERNMENT OF CANADA IS NOT FOLLOWING THE LEAD OF THE UNITED STATES IN LOWERING THE AGE FOR BREAST CANCER SCREENING FROM 50 TO 40:

• We recognize that the United States Preventive Services Task Force issued its final recommendations to lower the screening age from 50 to 40 on April 30, 2024.
• The Canadian Task Force on Preventive Health Care is an independent and arms-length organization responsible for developing clinical screening guidelines.
• The Task Force is currently undertaking an expedited update of its breast cancer screening guideline using the best available scientific evidence and considerations, including patients’ values and preferences.
IF PRESSED ON A POLL SUGGESTING THE MAJORITY OF CANADIANS ARE IN FAVOUR OF LOWERING THE BREAST SCREENING AGE:

• We are aware of the recently released Breast Cancer Canada and Angus Reid survey results, as are the members of the Task Force.
• Task Force guidelines and recommendations are established at arms-length from the Government of Canada, by using a rigorous review of all of the available scientific evidence and research.
IF PRESSED ON CONCERNS REGARDING ALLEGED BIAS FROM THE TASK FORCE CO-CHAIR:

• We are aware that some stakeholders expressed concerns regarding the leadership of the Task Force.
• Officials at the Public Health Agency of Canada have followed up with the Co-Chairs of the Task Force and have shared concerns with them.
• The Task Force Co-Chairs have reaffirmed their commitment to ensure that recommendations are based on evidence and approved by all members of the Task Force, with input from experts and patients.
• The Agency is regularly engaging with the Task Force to keep apprised of the work of the Task Force.
IF PRESSED ON PROVINCES AND TERRITORIES NOT FOLLOWING THE TASK FORCE GUIDELINES:

• The mandate of the Task Force is to develop clinical practice guidelines that support primary care providers.
• The Task Force guidelines are not mandatory for provinces and territories to adhere to. However, most provinces and territories do not have the resources to develop their own guidelines and they often rely on national guidance.
• We are aware that a number of provinces and territories have recently announced changes to their breast cancer screening programs, expanding eligibility to those in their 40s via self-referral or other mechanisms.
• In their 2018 guideline, the Task Force did not comment on how screening programs should be implemented as this is outside of their mandate. However, they have recommended that women in their 40s who choose to be screened should have access to mammographies.

The Canadian Task Force on Preventive Health Care (Task Force) is an independent arms-length body of up to 15 clinicians and methodologists established and funded by the Public Health Agency of Canada (PHAC). The Task Force has developed evidence-based clinical practice guidelines on a range of topics that support primary care providers in the delivery of preventive healthcare.

PHAC’s role in the production of guidelines is to ensure rigorous and appropriate methods are used to analyze the scientific evidence that forms the basis for the independent recommendations made by the Task Force. PHAC scientific staff members are authors on Task Force guidelines but do not vote on nor endorse the recommendations.

Task Force Recommendations
Recommendations from the Task Force’s current guideline from 2018 apply to women aged 40 to 74 years who are not at increased risk of breast cancer:

• For women aged 40 to 49 years – do not screen with mammography.
• For women aged 50 to 69 years – screen with mammography every two to three years.
• For women aged 70 to 74 years – screen with mammography every two to three years.

These recommendations are conditional on the relative value a woman places on possible benefits and harms from screening and stress the importance of shared decision-making between women and their healthcare providers to support an informed decision. In addition, the recommendations are consistent with the Task Force’s previous recommendation in 2011, and those in the United Kingdom and Australia.

On May 9, 2023, the United States Preventive Services Task Force published a draft update to their 2016 recommendations. Their previous 2016 guideline aligned with the Canadian Task Force’s 2018 guidance. The updated recommendation, which was subject to public comment until June 5, 2023, lowers the age of first screening from 50 to 40. The change from age 50 to age 40 was based on trends in rates of breast cancer in this age group over time in the United States. It is also based on formal modelling commissioned for this guideline which indicated a small potential benefit for women in this age (1.3 additional breast cancer deaths averted per 1,000 women screened beginning at 40 compared to starting at 50). They also examined randomized controlled trials and observational studies but did not identify any that provided additional evidence for screening in this age group. They also concluded there is insufficient evidence to recommend for or against screening above the age of 74, or additional screening (e.g., ultrasound or MRI) for women with dense breasts.

A final version of the recommendations was published on the United States Preventive Services Task Force website and in the Journal of the American Medical Association (JAMA) on April 30th, 2024. The final version is consistent with the draft, but includes additional clarifications on the evidence behind the guideline, in response to public comments.

While important to be aware of international comparators, changes to guidelines are often made based on data specific to the jurisdiction. For example the US guideline change was based on their epidemiological data and modelling the American population. It will be important that any change to Task Force guidelines leverages Canadian data to the extent possible.

Federal/Provincial/Territorial and Stakeholder Considerations
Presently, the majority of provincial and territorial screening programs operate in adherence to the Task Force’s guideline. Alberta updated their screening guidelines in 2022, reducing the age for screening to 45 from 50. This was based on their local epidemiological data as well as modelling. Several provinces do permit screening earlier based on a care provider’s referral or self-referral. For example, in October 2023, the Government of Ontario lowered the eligibility age to self-refer for regular breast cancer screening to 40. New Brunswick made a similar announcement in September 2023. Self-referral for women in their 40s was already in place in other provinces (BC, NS, PEI).

Many stakeholders are supportive of the 2018 guideline, including the College of Family Physicians of Canada. In late 2022, the Canadian Partnership Against Cancer and the Canadian Cancer Society withdrew their support for the 2018 guideline and called on the Task Force to undertake a review of this guideline. The Nurse Practitioners’ Association of Canada withdrew their support of the 2018 guideline in early 2024.

Since the release of the 2018 guideline, some advocacy groups and researchers have publicly expressed concerns about several aspects of the guideline, including the age to screen, that it does not include recommendations on supplemental screening for women with dense breast tissue, and that it recommends against breast self-exams.

The Task Force made the decision to update their 2018 guideline in early 2023 prior to the release of the U.S. Preventive Services Task Force updated guideline. On June 7, 2023, the Task Force publicly announced that it would conduct an expedited review and update of its 2018 breast screening guideline.

On June 8, 2023, the Government of Canada announced up to $500,000 in additional funding for the Task Force to help with the expedited timeline for this project. The Task Force accepted evidence submissions from Canadians through an online portal during August 2023 for consideration for inclusion in their review of the evidence regarding breast cancer screening. Further, the Government of Canada announced its intention to host a knowledge exchange event to bring together experts, partners, those with lived experiences, and stakeholders, to discuss the current state of the science, including knowledge gaps, related to breast cancer screening. PHAC worked with officials from Health Canada, the Canadian Institutes for Health Research, the Canadian Partnership Against Cancer, the Canadian Cancer Society, the Canadian Breast Screening Network, and the Canadian Public Health Association to plan the Knowledge Exchange event which took place on September 26 and 27, 2023. A “What We Heard” report summarizing the findings, including the diverse viewpoints and perspectives expressed during the event, was published online on December 20, 2023, and shared with participants.

On November 15, 2023, the Task Force announced that the timeline for a draft guideline update would be revised to Spring 2024. A change in timeline was necessary given the volume and complexity of the evidence, which caused the evidence review and modelling teams supporting the Task Force to require more time. This new timeline provides more time for the generation of a robust and trustworthy evidence base, and allows the Task Force adequate time to evaluate this evidence and make recommendations.

• In 2020, an estimated 27,400 women in Canada were diagnosed with breast cancer and 5,100 died from the disease. One in eight (12%) women in Canada are expected to be diagnosed with breast cancer in their lifetime.
• External evaluations of the Task Force’s 2018 breast cancer guideline by the American College of Physicians in 2019, and independent researchers in 2022, rank the guideline amongst the highest quality in the world.