Breast cancer

You are here: 

Screening for breast cancer

Screening means checking or testing for a disease in a group of people who don’t show any symptoms of the disease. Screening tests help find breast cancer before any symptoms develop. When breast cancer is found and treated early, the chances of successful treatment are better.

Currently in Canada, screening for breast cancer is recommended for women of average risk between the ages of 50 and 69. Regular screening for breast cancer is recommended for this age group because about half of all new cases of breast cancer occur in women between 50 and 69 years of age. The most reliable way to find breast cancer early is screening mammography. Research also shows that regular mammography can significantly lower the risk that women in this age group will die from breast cancer.

Talk to your doctor about your personal risk for breast cancer and take advantage of screening tests or programs in your area.

Breast screening programs

Breast screening programs vary among the provinces and territories. Each program has its own specific guidelines. All provinces and some territories have organized breast cancer screening programs for women 50–69 years of age. If you are in this age group, your province will automatically invite you to take part in the breast screening program. The screening program will send a letter reminding you when to have your next screening mammogram. You can contact your provincial or local breast screening program to book an appointment. You don’t need a doctor’s referral to make an appointment.

Some programs allow younger or older women to participate. Check with your provincial or local screening program for details about screening mammography for your particular age group or if you have questions about participating in the program.

You and your doctor will receive the results of the mammogram. Your doctor will be notified if the screening mammogram reveals a change or an abnormality that needs follow-up. Based on this information, your doctor will decide if you need to have more tests. A diagnostic mammography is the most common follow-up test and is used to focus on a suspicious area.

Screening mammography

Provincial and territorial screening programs use screening mammography. A mammography is a low-dose x-ray of the breast. A screening mammography is used to look for breast cancer in women who don’t have any symptoms of the disease. It may be done in a clinic, screening centre or mobile screening mammography unit.

If you are 50–69: Have a screening mammography every 2 years.

If you are 40–49: Talk to your doctor about your risk for breast cancer, along with the benefits and potential risks of mammography. The benefits of regular mammography to screen for breast cancer in women younger than 50 are still unclear.

If you are 70 or older: Talk to your doctor about how often you should have a mammography.

Benefits and risks of mammography

Almost every test has benefits and risks, including mammography. Scientific evidence tells us that regular mammography screening leads to fewer women dying from breast cancer. This is because it helps find breast cancer when it is smaller and more treatable, which improves the chances of survival.

The following are possible risks of mammography.

False-positive results are test results that suggest someone has cancer when it isn’t present. False-positive results can occur in women of any age, but are most likely to occur in women 40–49 years of age. A false-positive mammography result can cause anxiety and stress. It can also lead to having painful and unnecessary testing to rule out cancer.

False-negative results are test results that suggest someone doesn’t have cancer even though it is present. False-negative results can cause a woman or her doctor to ignore symptoms that suggest breast cancer is present, causing a delay in diagnosis and treatment.

Exposure to radiation is a risk of mammography because it uses very low doses of radiation. The benefits of mammography and finding breast cancer early outweigh the risk of exposure to the small amount of radiation received during a mammography.

Find out more about mammography and its benefits and risks.

Know what puts you at high risk

Some women have a higher than average risk of developing breast cancer. You may be at a higher risk if you have:

  • a strong family history of breast cancer
  • certain gene mutations, such as the BRCA1 or BRCA2 mutation
  • a personal history of lobular carcinoma in situ (LCIS), ductal carcinoma in situ (DCIS), invasive breast cancer or atypical hyperplasia
  • dense breast tissue
  • received radiation therapy to the breast or chest

Talk to your doctor about your risk. If you are at higher than average risk, you may need a personal plan for testing. This may include:

  • mammography at a younger age
  • more frequent mammography
  • ultrasound or magnetic resonance imaging (MRI)

Find out more about risk factors for breast cancer.

Clinical breast exam (CBE)

A clinical breast exam (CBE) is a thorough examination of your breasts by a trained healthcare professional. It is used to check for abnormalities. Research has not shown that CBE is an effective screening tool, but it may still help doctors find an abnormality in the breast or armpit (also called the axilla).

Find out more about clinical breast exam (CBE).

Know your breasts

All women should be aware of what is normal for their breasts even if they get regular screening tests. Many women find their own breast cancer by noticing changes in the look and feel of their breasts.

Women can become familiar with their breast tissue by looking at and feeling their breasts. In the past, experts suggested that women should do this in a certain way each month. Research shows that this isn’t necessary. There really isn’t a right or wrong way for women to examine their breasts. They just need to know the whole area of their breast tissue well enough to notice changes. This includes the entire breast area up to the collarbone and under the armpits, as well as the nipples.

Tell your doctor about any unusual changes to your breasts. Most breast changes are not cancer. It may be normal for your breasts to be lumpy or tender before your period.

Questions to ask your healthcare team

To make the decisions that are right for you, ask your healthcare team questions about screening.


Dr Claude Perreault Harnessing the immune system to fight cancer

Read more

Funding world-class research

Icon - paper

Cancer affects all Canadians but together we can reduce the burden by investing in research and prevention efforts. Learn about the impact of our funded research.

Learn more