You are using an outdated browser. We suggest you update your browser for a better experience. Click here for update.
Close this notification.
Skip to main content Skip to search

Screening for Breast Cancer

Cancer screening is testing done on people who may be at risk of getting cancer, but who have no symptoms and generally feel fine. Screening can find breast cancers when they are small, less likely to have spread and more likely to be treated successfully. Women ages 50 to 74 have a lower risk of dying from breast cancer when they are screened regularly with mammograms. 

When to Get Screened

Breast cancer is the most frequently diagnosed cancer in Ontario women. Screening can find breast cancers when they are small, less likely to have spread and more likely to be treated successfully. That’s why regular breast cancer screening at the right time is so important. Your age and family medical history help determine when you should get screened:

  • If you are age 50 to 74, the Ontario Breast Screening Program (OBSP) recommends that most women in your age group be screened every 2 years with mammography. Find Ontario Breast Screening Program locations.
  • If you are age 30 to 69 and meet any of the following requirements, talk to your doctor about referral to the Ontario Breast Screening Program:
    • You are known to have a gene mutation (e.g., BRCA1, BRCA2).
    • You are a first-degree relative (parent, brother, sister or child) of someone who has a gene mutation (e.g., BRCA1, BRCA2).
    • You have a personal or family history of breast or ovarian cancer.
    • You have had radiation therapy to the chest to treat another cancer or condition (e.g., Hodgkin lymphoma) before age 30 and at least 8 years ago. 

For every 200 women screened in the Ontario Breast Screening Program, about 17 are referred for further tests and 1 will have breast cancer.

Screening Mammograms

Mammography remains the best screening test for most women. A screening mammogram takes an X-ray picture of the breast and can find changes in the breast even when they are too small for you or your doctor to feel or see. 

Mammograms are considered safe and use a low dose of radiation. The benefits of screening and finding cancer early are more important than any potential harm from the X-ray. Most women will have normal mammogram results.

How Effective Are Screening Mammograms?

  • Mammograms are the best way to find breast cancer early. But they are not perfect tests. Mammograms may miss some breast cancers. Also, some cancers develop in the time between screens. However, many studies have shown that regular mammograms reduce the risk of dying from breast cancer. 
  • Some breast cancers that are diagnosed through screening may never cause symptoms in a woman during her lifetime (i.e., over-diagnosis). Therefore, some women may have surgery or treatment for a breast cancer that would not have become life threatening. 

  • Not all cancers found at screening can be successfully treated.

To learn more about what happens during a mammogram and how to get ready for a mammogram, see the Mammogram FAQs.

Where to Get Screened

Women ages 50 to 74 can call the nearest Ontario Breast Screening Program location to make an appointment (a doctor’s referral is not needed).

Women in the North West and Hamilton Niagara Haldimand Brant regions may be eligible for screening in one of our mobile screening coaches.

If you think you may be at high risk for breast cancer, talk to your doctor about a referral to the High Risk Ontario Breast Screening Program based on family or medical history.

Ontario Breast Screening Program

The Ontario Breast Screening Program (OBSP) is a provincewide, organized screening program that provides high-quality breast cancer screening for Ontario women. The program provides screening for most women ages 50 to 74, and for women ages 30 to 69 who are confirmed to be at high risk of getting breast cancer.

The High Risk OBSP sites help manage referrals to the program for women who may be at high risk for breast cancer. To learn about the eligibility requirements for the High Risk OBSP, see Breast Cancer Screening for Women at High Risk. For women who have been confirmed to be at high risk for breast cancer, these sites offer yearly screening mammography and breast magnetic resonance imaging (or, if MRI is not medically appropriate, screening breast ultrasound). These sites also assist with follow-up services for women with abnormal screening results.

Screening Letters Sent to the Public

Cancer Care Ontario sends letters to women turning 50 inviting them to get screened for breast cancer through the Ontario Breast Screening Program. Women ages 51 to 73 who have not been screened in at least 3 years also receive a letter inviting them to get screened. 

We also send letters to women ages 50 to 74 reminding them when it is time to return (recall) for screening and informing them of their results, if they are normal. 

Letters Women May Receive

  • Correspondence privacy notice
  • Invitation letter
  • Invitation reminder
  • Recall letter (2 years)
  • Recall reminder
  • Normal result letter (1 year recall)
  • Normal result letter (2 year recall)
  • Normal result letter (no recall)

A sample of each letter type is available in the Letters to the Public area.   

Resources for the Public

Fact Sheets

Ontario Breast Screening Brochure

The brochure called “Breast Cancer Screening – it’s never this obvious” provides information on when it is the right time for you to start screening.

Public Health Agency of Canada Brochures

Helpful Websites

Resources for Newcomers and Immigrants

When you arrive in a new place, it’s important to keep your health at its best. Part of that may involve getting screened for breast cancer:

Dina’s Breast Cancer Screening Story (Arabic)

Learn about how Dina from Sudan was hesitant to have a mammogram because she heard that they were painful. She changed her mind when she attended an educational workshop about cancer screening. 

Transcript – Dina


Hasina’s Breast Cancer Screening Story (Bengali)

Learn about how Hasina, a newcomer to Ontario, overcame her fear of breast cancer screening and now gets regular mammograms. Hasina also encourages other women to get mammograms.

Transcript – Hasina


Rose’s Breast Cancer Screening Story (Mandarin)

Learn about how Rose overcame her fear of breast cancer screening and was diagnosed with early-stage breast cancer through a mammogram. She has fully recovered and has regular mammograms.

Simplified Chinese

Traditional Chinese

Transcript – Rose


Vanita’s Breast Cancer Screening Story (Hindi)

Vanita came to Canada from India. One of the first medical tests she had in Canada was a mammogram. The doctor told her that if breast cancer is caught early, it is easier to treat. She gets tested regularly and encourages her friends to do the same.

Transcript – Vanita