What is dense breast tissue?
Dense breast tissue is comprised of less fat and more connective tissue which appears white on a mammogram. Cancer also appears white thus tumors are often hidden by the dense tissue. As a woman ages, her breasts usually become fattier.
However, 2/3 of pre-menopausal and 1/4 of postmenopausal women (40%) have dense breast tissue. Radiologists have been reporting a woman's dense breast tissue to her referring doctor for twenty years. Most often, that information is not conveyed to the patient. Displaying heterogeneously or extremely dense breast tissue on a mammogram is considered dense (BIRADS C, D).
How is dense breast tissue determined?
- Breast density is determined through mammography.
- If you haven’t had a mammogram, then you have a 40% chance of having dense breasts over the age of 40. Chances are increased for women under 40.
- Cancer is 4-6 times more likely to be missed in women with extremely dense breasts than in women with fatty breasts.
- Mammography does find cancers in women with fatty breasts. It’s like looking through a window.
- Mammograms will miss about 50% of the cancers that are present Heterogeneously dense breasts.
- Breast cancer screening tests, such as tomosynthesis (3D mammography) or breast MRI, in addition to a mammogram substantially increase detection of early stage breast cancers in dense breasts but posing a risk to increase your chances of breast cancer.
Fatty - The breast tissue is fatty tissue and is easy for diagnosis.
Fibroglandular Dense - the breast is mostly fat tissue but has scattered Fibro-glandular tissue that may obscure the mammogram allowing for false positive diagnosis.
50% OF WOMEN SCREENED ARE HETEROGENEOUSLY DENSE OR EXTREMELY DENSE.
Heterogeneously Dense - 40% of the women fall into this category. 50% of the breast tissue is dense, and the remaining tissue is fatty. But the Fibro-glandular tissue is scattered in the mammography image tightly bound together obstructing the radiologist's view of cancer or mimicking cancer resulting in a false positive diagnosis.
Extremely Dense - 10% of these women are extremely dense. Meaning 75% of the breast tissue is dense, and the remaining tissue is fatty. The highest risk of missing cancers in mammography.
If you haven't had a mammogram, then you have a 50% chance of having dense breasts.
- The sensitivity of mammography is reduced as background breast tissue density increases.
- When mammography is the only screening test performed, sensitivity decreases by 10% to 20% for women with "dense breasts".
- Cancer is 4-6 times more likely to be missed in women with extremely dense breasts than in women with fatty breasts.
- Mammograms will miss about 50% of the cancers that are present in women with Heterogeneously dense breasts. It's like looking for a snowball through a snow storm.
- Mammography does find cancers in women with fatty breasts. It's like looking for a snowball through a window on a bright day.
- Breast cancer screening tests, such as tomosynthesis (3D mammography) or breast MRI, in addition to a mammogram substantially increase detection of early stage breast cancers in dense breasts but posing a risk to increase your chances of breast cancer.
BREAST ULTRASOUND SAVES LIVES