Breast Cancer · June 7, 2021

My mammography report says I have dense breasts. Does it mean I have a higher risk of breast cancer?

2 minute read

Your breasts are composed of varying proportions of fibroglandular ( breast tissues ) and fatty tissue ( the supporting network ). The mammography report always makes a mention of the breast density on mammography. Breast density is a descriptor to describe how much proportion of fibroglandular tissues which appears white and fatty tissue which appears black on mammography, are present in the breasts on mammograms. It signifies the ability of the radiologist to pick abnormalities in breasts.

Breast density depends on various factors such as age and race. Women of certain races for example asian women have dense breasts compared to their western counterparts. When a woman is young ( in her 30’s) her breasts are usually composed almost entirely of fibroglandular tissue and appear dense on mammogram on the other hand in older women( in her 60’s) the breasts are almost entirely fatty.

The radiologist can have difficulty in picking up abnormalities (such as cancer, calcifications etc.) in dense breasts as these appear white on a background of dense breasts which also appears white. The breast density are can vary from a- almost entirely fatty to d- dense fibroglandular on mammography. The descriptors used for breast density on mammography reports are-
a: the breasts are almost entirely fatty
b: there are scattered areas of fibroglandular density
c: the breasts are heterogeneously dense, which may obscure small masses
d: the breasts are extremely dense, which lowers the sensitivity of mammography

Women with c and d type of density may have dense breasts and it becomes difficult for radiologists to pick up breast masses/ cancers on mammography alone. Therefore the radiologist may ask for supplemental imaging such as a 3D mammogram, an ultrasound or breast MRI.

It becomes difficult for radiologist to pick up an abnormality in dense breasts as both the fibroglandular breast tissues and the mass or abnormality appear white on mammogram. Many studies have found a higher risk of breast cancer in dense breasts. Further more the risk of breast cancer increases due to the reduced senstivity of mammography in such cases.

Be Aware of your breast density and in case you have dense breasts, consult your radiologist and discuss the supplemental imaging you may need along with your mammography.


This information is for general guidance and reflects the opinions and experience of the author. It is not intended to replace specialist consultation or provide treatment advice for specific cases.