Breast Cancer Screening

Topic Overview

The type and frequency of breast cancer screening changes as you age. You should discuss the benefits and harms of mammograms with your doctor. He or she can help you decide when to start and how often to have a mammogram.

Guidelines for when to start having breast cancer screening and how often it should be done vary from province to province. Your doctor can help you find a breast cancer screening program in your area.

For women who are at average risk for breast cancer, the Canadian Task Force on Preventive Health Care recommends the following guidelines.footnote 1

  • Ages 40 to 49: Regular mammograms are not recommended.
  • Ages 50 to 74: Regular mammograms (every 2 to 3 years) are recommended.
  • Age 75 and older: You may want to talk to your doctor about whether you need breast cancer screening.

If you have high risk: Talk to your doctor about how often you need screening if your mother, sister, or daughter had breast cancer or you have a family history of cancer. You may need a referral from your doctor to have a mammogram.

You can find out your personal risk level at

Early detection is an important factor in the success of breast cancer treatment. The earlier breast cancer is found, the more easily and successfully it can be treated. Tests used for screening include:

  • Mammogram. A mammogram is an X-ray of the breast that can often find tumours that are too small for you or your doctor to feel. Standard mammograms use film to record images of the breast, but most mammograms done now are digital mammograms. Digital mammograms record images of the breast in an electronic file.
  • Digital breast tomosynthesis (3-D mammogram). This test uses X-rays to create a three-dimensional image of the breast. This is a newer test that may be used alone or with a digital mammogram.

Make sure you know what your breasts normally look and feel like. When you know what is normal for you, you are better able to notice changes. Tell your doctor right away if you notice any changes in your breasts.

Magnetic resonance imaging (MRI) of the breast may be used as a screening test for women who have a high risk of breast cancer. This includes women who test positive for the BRCA1 or BRCA2 gene, or have two or more close family members who have had breast cancer before age 50. MRI may also be useful for women who have breast implants or for women whose breast tissue is very dense.

Your breast density can affect how clearly your breast tissue can be seen on a mammogram. Still, if you have dense breasts and if nothing else increases your risk for breast cancer, a mammogram is the recommended test for you.

For more information, see the topic Breast Cancer.

See also:

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  1. Canadian Task Force on Preventive Health Care (2018). Recommendations on screening for breast cancer in women aged 40–74 years who are not at increased risk for breast cancer. CMAJ, 190(49): E1441–E1451. DOI: 10.1503/cmaj.180463. Accessed December 20, 2018.

Other Works Consulted

  • American College of Obstetricians and Gynecologists (2011). Breast cancer screening. ACOG Practice Bulletin No. 122. Obstetrics and Gynecology, 118: 372–382.
  • Oeffinger KC, et al. (2015). Breast cancer screening for women at average risk 2015 guideline update from the American Cancer Society. JAMA, 314(15): 1599–1614. DOI: 10.1001/jama.2015.12783. Accessed January 21, 2016.
  • Siu AL, U.S. Preventive Services Task Force (2016). Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Annals of Internal Medicine, published online January 12, 2016. DOI: 10.7326/M15-2886. Accessed January 12, 2016.


Current as of: August 22, 2019

Author: Healthwise Staff
Medical Review:
Sarah Marshall MD - Family Medicine
Anne C. Poinier MD - Internal Medicine
Kathleen Romito MD - Family Medicine
Douglas A. Stewart MD - Medical Oncology

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