Breast Cancer Screening Guidelines Putting Thousands of Women at Risk

The new breast cancer screening guidelines are dangerous, and thousands of Canadian women will die if they are not revised.

In December 2018, the Canadian Task Force on Preventative Health Care issued guidelines on breast cancer screening for women of average risk. These guidelines are used by 36,000 family doctors in their interactions with 9 million women aged 40-74. Here’s why they are putting thousands of women at risk:

1. The guidelines ignore expert advice.

There are no breast cancer experts on the Task Force. The members have no experience in reading screening mammograms or treating patients with breast cancer. They consulted experts, but ignored their input – and stated that this was done to prevent expert bias. Over 130 breast cancer experts have strongly criticized the guidelines.

2. The guidelines ignore the importance of screening for women in their 40s.

1/6th of breast cancer deaths and 24% of the years of life lost to breast cancer are in women diagnosed in their 40s. Even with these statistics, the Task Force does not recommend screening for women in their 40s. If this recommendation is followed, 4,000 Canadian women will die over the next decade.

3. The guidelines advise against breast self-exams.

These exams are an important measure woman can take to increase early detection of breast cancer, especially in women with dense breasts.

4. The guidelines exaggerate the harms of recalling women for additional testing after a mammogram.

About 10% of women are recalled for additional images, and this may cause anxiety. The Task Force considers this anxiety to be harmful and uses it to dissuade women from screening. However, this anxiety has been shown not to be long-lasting, and it’s a small price to pay to determine whether cancer is present or not. Better safe than sorry.

5. The guidelines ignore significant health benefits of early cancer detection.

The Task Force does not acknowledge the benefits of avoiding chemotherapy, avoiding mastectomy, and avoiding lymphedema.

6. The guidelines ignore current data.

The Task Force relies on outdated data and flawed studies. These studies are obsolete, and estimate that women are 15-20% less likely to die if they have breast screening. Current studies show that women who have mammograms are actually 40-44% less likely to die of breast cancer than those who do not.

7. The guidelines ignore the risks of breast density.

The risks of dense breasts have been known for 40 years. Dense breasts increase the risk of developing breast cancer and increase the risk that cancer will be masked on a mammogram. The guidelines ignore the benefits of supplemental screening for women with dense breasts.

8. Women are being asked to make decisions about life-saving screening based on inaccurate information.

Using the new guidelines, which exaggerate the harms and understate the benefits of screening, women may make decisions that could ultimately lead to a late diagnosis, unnecessary suffering, and a poorer prognosis.


All Canadians should be outraged by these guidelines. Canadian women and their family doctors deserve to have accurate information about the benefits of screening. In fact, a group of physicians from different specialties wrote a letter in the CMAJ due to concern about the denigration of expert opinion, and worry that patients will be affected by the inaccurate and dangerous guidelines.

You can help by signing and sharing the petition. Join the 52,000 voices telling Health Minister Petitpas-Taylor that the new screening guidelines for breast cancer must be rejected because they are dangerous and will cause loss of life.


Find the petition here.