Dr. Jean Seely
President, Canadian Society of Breast Imaging (CSBI)
Screening is the method of detecting a cancer before it’s found by symptoms such as a lump at breast examination, skin dimpling, or a suspicious bloody or watery nipple discharge. Screening mammography identifies breast cancers at a smaller stage, before they can be felt, and when they’re less likely to have spread to other parts of the body. Screening is associated with a 40%–60% lower risk of dying from breast cancer and decreases the need for more aggressive breast surgery, like a mastectomy, or therapy (chemotherapy or radiation).
The Canadian Society of Breast Imaging (CSBI) recommends screening mammography for women between the ages of 40 and 74, every 1 to 2 years. For women older than 74, screening should continue if life expectancy is over 7 years. A loss of 420 lives every year in Canada is calculated if women don’t follow this screening recommendation. Women 40 years and older should request a screening mammogram from their doctors.
Women should also be aware of whether they have dense breast tissue, as this makes finding early cancers more difficult. The only way to identify dense breast tissue is with a mammogram. While a mammogram can detect cancers in women with dense breast tissue, any additional signs of breast cancer such as changes of the nipple, a new lump, or skin changes should be carefully noted and brought to medical attention and should be investigated further with a clinical breast examination and ultrasound.
Women with dense breast tissue may benefit from the newer type of 3D mammogram called tomosynthesis to help improve the accuracy of screening. They may also benefit from screening with ultrasound or breast MRI in addition to the mammogram. Any additional risk factors such as a family history of breast cancer should be noted. A strong family history of breast cancer, such as one or more affected first-degree (sister, mother) or second-degree (grandmother) relatives, may indicate that a woman is at high risk for breast cancer. High-risk means she has higher than a one in four chance of getting breast cancer. High-risk women should be screened with mammography plus breast MRI every year.