Thank you.
I'm a family doctor and a GP-oncologist. I work with Statistics Canada and the Canadian Cancer Registry to look at real-life cancer outcomes. I have a unique vantage point to understand the impacts of breast cancer screening recommendations across our entire health care system.
My research with Statistics Canada has focused on breast cancer in women in their forties. We found the incidence of breast cancer in these women has increased almost 10% in recent years and that women with access to organized breast screening programs have an earlier stage at diagnosis and significantly increased survival. We've also found that women in their forties have more aggressive subtypes of breast cancer, where the survival for cancers diagnosed beyond stage 1 drops off dramatically.
We've shown that the peak age for breast cancer diagnosis among white women is 65, but for women of other races and ethnic groups, it's typically before 50. These same women have significantly more advanced stage cancers at diagnosis. This work has been done in spite of the fact that our national cancer data has significant gaps that limit our analytical abilities.
We've established that the costs of breast cancer treatment rise exponentially with later stages of diagnosis. Our cost-effectiveness analysis has shown that screening at age 40 saves lives and saves our health system half a billion dollars annually, as it's so much more expensive to treat advanced cancers than it is to do screening.
I was an invited expert on the evidence review for the 2024 breast cancer screening guidelines, an experience that highlighted critical flaws in the process. The task force ignored our expert recommendations, with the end result being that the benefit of screening was minimized. The task force dictated the terms of the evidence review, mandated the use of old studies and insisted on too short a time frame to show the full benefits of screening. It determined the benefit of screening in women 40 to 49 by extrapolating the benefit from older women, even though trials looking specifically at women 40 to 49 showed higher benefits, in the range of 44% to 57% mortality reduction. It did the same with dense breasts and family history; it merely extrapolated the benefits observed in average-risk women. The task force had access to race and ethnicity data from StatsCan but did not act on the age of earlier diagnosis in all women other than white. We experts voiced our concerns in a limitations document, which was ignored.
Even if we use the task force bias and minimize mortality benefits of only one death averted per 1,000 women screened over 10 years, this amounts to over 2,500 deaths of 40-year-old women. This number somehow did not reach their threshold of significance, a threshold that seemed inconsistent between guidelines. The real number of deaths, based on modelling, is threefold or fourfold higher.
Concerningly, the 2018 task force 1,000-person tool, which Canadian family doctors used for six years to counsel their patients, contains serious errors. The 2018 tool notes that there were seven cancers per 1,000 women, while the 2024 tool now states that there are 19 cancers per 1,000 women. The 2018 number was incorrect. The 2018 tool used an overdiagnosis rate of 48%, while the 2024 review found this number to be 3%. These incorrect numbers caused the 2018 tool to show a minimal benefit of screening. The task force misinformed Canadian family physicians and their patients for years with the very tools designed to facilitate shared decision-making and with no apparent explanation.
The task force is a venerable institution, and busy family physicians use its guidelines to inform discussions with patients. Despite provincial practices, the task force recommendations matter. They cause family physicians to dissuade patients from screening or to not even broach the topic. They create confusion, as their recommendations are often different from specialist guidelines. They create an unconscious bias that younger women don't get breast cancer. The task force drives inequities as provinces institute different programs based on their own interpretations of the evidence.
Disturbingly, the issues we face with breast cancer guidelines are just the tip of the iceberg. We hear about breast cancer, as there are passionate advocates placing these issues front and centre. Similar outdated and nonsensical recommendations exist for lung and cervical cancers and in many other realms, broadly impacting women's health.
We must have a transparent guideline process that is nimble and responsive and reflects current evidence. Our national guidelines should be unifying and effectively incorporate Canadian subject matter expertise. We should strive for guidelines that remove barriers to accessing care, embrace an individual's autonomy to make decisions about their own health, and support equitable access to life-saving cancer screenings.
Thank you.