Dense breast tissue refers to the way breasts look on a mammogram.
“Know your breast density and make it part of the conversation about your screening plan with your Radiologist or GP.”
Dr Carole Paulus, Radiologist – Beyond Radiology Silverdale.
Dense breasts are normal and have nothing to do with breast shape or size. Breasts are made up of dense breast tissue and fatty breast tissue. A person with dense breast tissue has more dense tissue than fatty.
Almost half of women over age 40 have dense breasts, and this can affect breast cancer screening in two ways:
Dense breast tissue can hide cancer on a mammogram:
Cancers can be hidden and missed until they are larger and more likely to have spread.
Dense breasts increase the risk of getting breast cancer:
The denser the breast, the greater the risk. This doesn’t mean that having dense breasts alone puts you at high risk for breast cancer, but it is another risk factor to add to the list when considering your lifetime risk – just like age, family history of breast or ovarian cancer, gene mutations, taking hormones etc.
How do I know if I have dense breast tissue?
Dense breast tissue cannot be felt by a woman during a self-exam or by doctors during a clinical breast exam. Breast density can only be determined on a mammogram or MRI. If you previously had a mammogram, your report should include your breast density. Radiologists worldwide usually follow the BI-RADS classification system which describes four categories of breast density:
A: Almost entirely fatty
B: Scattered areas of fibroglandular density
C: Heterogeneously dense
D: Extremely dense
Categories C and D are considered dense. A and B not dense.
Cancer screening for women with dense breasts
“If you are in the D category – with extremely dense breast tissue – mammography alone is limited for early breast cancer detection. This does not mean that you should stop having mammograms as this can still show signs of breast cancer, but you will benefit from supplemental screening with ultrasound”, says Dr Carole Paulus, Radiologist at Beyond Radiology Silverdale.
Research also shows that 3D mammograms or Tomosynthesis are more accurate than 2D mammography, particularly for women with type C breasts.
“At Beyond Radiology, all our patients receive a 3D mammogram as standard. If we feel that an additional screening ultrasound is indicated, we will clearly communicate this in our report”.
Research also shows that contrast-enhanced MRI can significantly reduce breast cancer mortality in women with type D breasts.
This is unfortunately not yet routinely offered to patients in New Zealand but will likely play a much bigger role in breast cancer screening in dense breasts in the near future.
Remember to know your breasts and that the answer to this simple question could save your life: “Are my breasts dense?”.
If you don’t know the answer yet, we encourage you to ask the question at your next mammogram and if the answer is yes, discuss supplemental screening with your Radiologist or GP.