No screening test is perfect, and mammography is no exception. Factors like age or breast density can influence the look of breast tissue on a mammogram, making cancers more or less difficult to recognize. But many cancers are found on mammograms
even if dense breast tissue is present.
There is no current policy regarding the reporting of dense breast tissue in Canada. Further studies are required to determine if additional screening tests are appropriate for women with increased breast density, including an understanding of the advantages and disadvantages of additional testing.
At present, in BC and in Canada, a breast density assessment from a mammogram is subjective; therefore the accuracy of determining breast density from a mammogram at this time would be questionable and could lead to a lot of unnecessary concern and follow-up.
Mammograms are the screening test proven to reduce breast cancer deaths. Being “breast aware” is always an important component of breast health and any breast changes should be discussed with your health care provider right away, even if you have had a recent mammogram.
At the BC Cancer Agency we are looking at ways to diagnose women with dense breast tissue, and the effectiveness of different screening options if we can accurately identify those with dense breasts. In fact, we are in the process of initiating a clinical trial to look at a new 3D imaging technology for breast screening, which may be more effective at screening women with dense breast tissue. There are also some potential software tools under development to determine breast density. We are watching these, and although they will require scientific validation prior to use, they could provide women with an accurate measure of breast density in the future, at which time we would look to implement a system provincially.
The BC Cancer Agency is dedicated to improving the detection of cancer, and the Screening Mammography Program of BC is no exception. We continue to assess the latest evidence and tools available to better detect, prevent and treat cancer.