Breast Cancer—Patient FAQ

The Canadian Task Force on Preventive Health Care recommends that women aged 50–74 schedule a mammogram every 2–3 years.i

Who is considered at ‘high risk’?

High risk refers to women who have a personal or family history of breast cancer, and/or a gene mutation known as BRCA1 or BRCA2, and/or prior chest wall radiation. The BRCA1 and BRCA2 gene mutation greatly increases a person’s risk of breast cancer. This guideline does not apply to women with a high risk of breast cancer. If you are high risk, consult a physician about the best screening options for you.

Why are these recommendations important?

Breast cancer is the second most common cause of cancer deaths among women aged 40–79. In 2010, approximately 80% of new breast cancer cases diagnosed in Canada were in women older than 50, and of those, approximately 28% were in women 70 or older.

What does breast cancer screening mean?

Breast cancer screening is trying to detect cancer when symptoms are not present.

What is the best way to screen for breast cancer?

The most common method of breast cancer screening is with a special x-ray called mammography. A mammogram takes x-ray images (film or digital) of the soft tissue of the breast to look for signs that breast cancer may be developing, even if there are no previous symptoms. Other methods such as ultrasounds are also used under certain circumstances, but mammography has been shown to be the most effective method of screening for breast cancer in its early stages.

What are some of the harms associated with mammography?

Detecting cancer requires tests such as mammography (x-rays) and biopsies (taking a sample of the breast tissue to look for signs of cancer under a microscope). Because these tests are not always accurate, screening can lead to unnecessary testing or breast surgery in women without cancer. However, it can also prevent unnecessary deaths in women who have breast cancer that has not yet been detected. Some of the harms that can be associated with mammography are false positives, where a screening test indicates that you might have cancer when in fact you do not. False positive results may lead to anxiety, unnecessary biopsies, lumpectomy (removing a lump in the breast, whether cancerous or not) and/or mastectomy (removal of a breast).

What are the benefits from screening with mammography?

Screening with mammography modestly reduces the number of deaths from breast cancer, with the greatest impact being in women 50–74 years.

Why do the guidelines suggest a mammogram every 2–3 years for women 50–74 years?

The recommendation to screen every 2–3 years is based on evidence that takes into account the associated harms of screening and found no difference in benefit (ie: reducing the number of deaths) between screening every 2–3 years and screening annually. This recommendation is similar to guidelines from the United Kingdom (every 3 years) and the United States (every 2 years).

What does the Task Force recommend for Breast Self Examination (BSE) and Clinical Breast Exam (CBE)?

The Task Force recommends against routine BSE (self-examination of the breast) and CBE (examination performed by a health professional), after their review found that neither reduced breast cancer or related deaths in women aged 40–74. Furthermore, two large studies identified no reduction in deaths from breast cancer associated with teaching BSE to women aged 31 to 64, but found evidence of increased harm.


  1. Does not include women who are at high risk for breast cancer.