Anna Wilkinson is an associate professor in family medicine at the University of Ottawa and a GP oncologist at The Ottawa Hospital Cancer Centre.
There is a disconnect between the Canadian breast cancer screening guidelines, which tell doctors not to screen women in their 40s, and the young women I look after in the cancer wards, dying of metastatic breast cancer. As a family doctor, I’m instructed not to screen women age 40 to 49 for breast cancer, but in hospital, I care for these young women, dying from breast cancer that was caught too late. With a U.S. health panel now recommending screening women in their 40s, Canada should also look to revise its screening guidelines.
Sometimes these women die from liver failure as the cancer replaces their liver, or respiratory failure from lungs filling up with tumour and fluid, often with pain from crumbling bones. But there are always hard conversations with these women, their children, partners and parents, trying to explain the unexplainable, because women in their 40s and 50s should not be dying.
Family doctors and nurse practitioners follow the Canadian Task Force on Preventive Health Care for breast cancer screening guidelines. In 2011, the task force recommended against screening for breast cancer with mammography for women in their 40s, a stand which they reconfirmed in 2018. Although “shared decision-making” is encouraged, women seeking screening in their 40s are often refused because of the recommendation for no screening. The Canadian Cancer Society withdrew their statement of support for these guidelines last December. The U.S. Preventive Services Task Force updated their guidelines on Tuesday, saying that all women should start breast screening at age 40.
Breast cancer in women in their 40s is an unfortunate reality. One in five breast cancers are diagnosed in this age group. In Canada, some provinces and territories screen women 40 to 49 and others do not. Along with radiologist Jean Seely, and Statistics Canada, I studied how these differences in screening affect breast cancer stage at diagnosis. We found that provinces and territories with no screening for women in their 40s have significantly more advanced and incurable breast cancer. Not screening women earlier also causes significantly more advanced cancers in women in their 50s, with a 10.3 per cent increase in incurable or metastatic disease for these women since the guidelines for women in their 40s changed in 2011.
Mammograms find cancers when they are tiny, before they can be felt. Once you can feel a cancer, it is already more advanced. Whether a cancer is advanced or not really matters – for both treatment and survival. Early cancers need less invasive surgery, less intensive treatment and less health care resources. And most importantly, early cancers mean less chance of dying. The five-year survival for Stage 1 breast cancer is 99.8 per cent, while Stage IV cancers are incurable.
So why do the Canadian guidelines tell doctors not to screen these women? The guidelines are based on old studies from the 1960s, ‘70s and ‘80s. The diagnosis and treatment of breast cancer has changed radically since these studies, as has the makeup of our society. Black, Hispanic and Asian women have a peak incidence of breast cancer in their 40s, while the peak in white women is in their 60s. The trials that we rely upon for screening younger women were done in predominantly Caucasian populations that don’t reflect the multicultural makeup of our society today. The guidelines also rely heavily on a discredited study, which has been criticized for randomization issues.
We can debate ad nauseam about anxiety and overdiagnosis, the oft-cited reasons not to screen women in their 40s. But to label women as “anxious” because of cancer screening is, frankly, paternalistic and outdated. Women should be able to make their own choices about their bodies and health. There is nothing more anxiety-provoking than a diagnosis of metastatic breast cancer – especially one that could have been avoided.
Common sense tells us that “an ounce of prevention is worth a pound of cure.” It is time to listen to the Canadian Cancer Society and the new U.S. guidelines and re-evaluate the guidance that doctors like me receive for screening women in their 40s. It’s time to throw out outdated trials that don’t reflect today’s technology and treatments and our current population. It’s time to look at the cost savings to our system when we screen and treat breast cancer at an earlier stage. It’s time to consider modern population-based evidence, which clearly shows that screening saves lives. It is time to end the disparities between provinces and territories and start screening all Canadian women in their 40s for breast cancer. This way, we can stop having difficult conversations with women about why they are facing death at such a young age.