Dense Breasts and Screening Mammograms

What is breast density?

Women’s breasts are made up of glandular, connective tissue and fatty tissue. Breast density is a measure of the proportion of glandular, connective and fatty tissue on a woman’s mammogram. Women with more glandular, connective tissue than fatty tissue are said to have dense breasts.

Who is likely to have dense breasts?

Dense breast tissue is common and normal. Anyone can have dense breasts, however typically younger women have denser breasts than older women. As women grow older, their breasts often become more fatty and less dense.

How is it determined if a woman has dense breasts?

The amount of density a breast has cannot be felt by a physical examination. A mammogram is required to determine if a woman has dense breasts. The radiologist who reads a woman’s mammogram determines the ratio of fatty tissue to dense tissue and assigns a level of breast density.

How do dense breasts show up in a mammogram?

On a mammogram, fatty tissue appears dark. Dense breast tissue appears as a solid white area on a mammogram.

Why is breast density important for women to know about?

Very dense breast tissue may sometimes make reading a mammogram difficult and can mask a mass. In addition, women with a high breast density are thought to have an increased risk of developing breast cancer.

What happens when a women with dense breasts has a mammogram through the Saskatchewan Cancer Agency’s Screening Program for Breast Cancer?

If your mammogram shows that your breasts have 75 per cent or more dense tissue, the radiologist will recommend that you have an annual mammogram. Having an annual screening mammogram is recommended to help detect even small changes in the breast. If you have dense breasts you may also want to discuss options with your healthcare practitioner.
Modern mammography equipment use very low doses of radiation.

Breast Density and Screening Mammograms

Breast density can only be seen on a mammogram. It is not related to breast size or firmness. Dense breasts may mask small breast masses and have a higher risk of developing breast cancer than fatty breasts. If you have a density of 75 per cent or greater it is recommended that you have an annual mammogram. You may also want to discuss options with your healthcare practitioner.

Below are images that show how various levels of breast density appear on a mammogram.

Screening Breast Dense Breast Image

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