In the news: the debate over breast cancer screening

04 November 2015


Our understanding of the benefits and harms of breast cancer screening continues to evolve.

You may have heard in the news last month that the American Cancer Society is now recommending that women should start screening for breast cancer with mammography at age 45; they previously recommended starting at age 40.

But many other health organizations, including the Canadian Cancer Society, recommend that women wait until the age of 50 to begin regular breast cancer screening. Both Alberta Health Services and the Government of the Northwest Territories also recommend waiting until the age of 50.

We understand it can be very confusing to have different recommendations coming from various health groups. That’s why we’ve asked Rob Nuttall, an expert on cancer control issues such as prevention and screening, to bring some clarity to this debate.

Why are there different screening guidelines?

The updated American Cancer Society recommendations are closer to Canadian Cancer Society recommendations and those of other major health organizations, although some differences do exist.

These differences are a result of the expert panel taking into consideration US demographics and cancer trends, healthcare delivery, and patient values and preferences.

Will these recommendations have an impact on screening in Canada?

The changes to the American Cancer Society’s recommendation will not affect the recommendations of the Canadian Cancer Society, or provincial/territorial screening programs.

The Canadian Cancer Society recommendations are also based on scientific literature and are informed by the Canadian context.

The Society’s recommendations are in line with other major organizations like provincial/territorial screening programs, the Canadian Task Force on Preventive Health Care and the International Agency for Research on Cancer (an agency of the World Health Organization). 

What are the benefits and harms of screening?

Almost every medical procedure has benefits and risks. It’s important to be aware of them so that you can make an informed decision that’s right for you.

Women who have regular mammograms are more likely to survive breast cancer and have a better quality of life through less treatment and less time recovering; however, having regular mammograms can lead to the test suggesting cancer even though cancer is not present (a false positive) or finding cancers that may never cause any symptoms or decrease life expectancy or quality of life (overdiagnosis).

What should you do?

The Canadian Cancer Society recommends that:

  • women aged 50 to 69 have a mammogram every two years
  • women aged 70 and older should talk to their doctor about how often to have a mammogram
  • women aged 40 to 49 should talk to their doctor about their risk of breast cancer and about the benefits and risks of mammography

Each province sets their own guidelines for their breast cancer screening programs. In Alberta, women aged 50 to 74 are automatically enrolled in the province’s breast cancer screening program and can receive regular mammograms.

If you are a woman in the eligible age group for screening in your province, talk to your doctor about getting regular mammograms to reduce your risk of dying of breast cancer.

More information on the Society’s recommendations for breast cancer screening can be found here on

Rob Nuttall is the Assistant Director, Cancer Control Policy, with the National Office of the Canadian Cancer Society. Rob and his team work across the cancer control spectrum, from prevention and screening to end-of-life care. Rob has spent his career in the field of cancer control, from doing laboratory-based biomedical research to informing health policy activities for the Canadian Cancer Society. After completing his PhD in Physiology from the University of Western Ontario, he spent several years in England and Halifax as a cancer researcher and eventually transitioned into doing research on science policy. He joined the Canadian Cancer Society in 2009 as a Health Policy Analyst with the Cancer Control Policy team.

Back to the November 2015 issue of Cancer Challengers