Breast Density

No - many women have "lumpy" breasts which is usually related to the combination of glandular tissue and fatty tissue in the breast, but lumpy is not the same as dense. Breast density refers to the appearance of the breast tissue on imaging, usually mammogram. Dense breast tissue appears more "white" on mammogram, which makes it harder to detect cancer, also usually "white" on mammogram. Younger women naturally have dense breast tissue, but some women still have dense breast tissue even as they get older. Hormone therapy will maintain the dense breast appearance on mammogram.

Women with dense breast tissue on imaging are at higher risk for the future development of breast cancer, and as mammograms may miss more cancers in women with dense breast tissue, additional imaging such as ultrasound or MRI may be helpful.

That's a good question, especially with all the information we now have linking breast density to an increased risk of breast cancer. Density refers to relative proportion of fibrous or glandular tissue to fatty tissue in the breast and is most commonly evaluated by appearance of the tissue on mammogram. Dense tissue is not the same as "lumpiness" - a woman can have a lot of lumpy breast tissue but the tissue could be primarily fat. In general, breast density does decrease with age - the normal aging process makes the breast tissue more fatty over time. This results in easier interpretation of mammograms and other imaging studies as women get older as it is harder to "see through" the dense breast tissue on mammogram to identify tumors - this is a major reason why mammograms and even ultrasound and MRI have a harder time detecting breast cancer in younger women.

Breast density is not only influenced by age however. Women that are on hormone replacement therapy will generally continue to have dense breast tissue even after menopause, and some women even without HRT have dense breast tissue - genetics, body weight, diet, activity and other factors probably play a role as well.

It is important to know that your risk of breast cancer is increased if you have dense breast tissue, but the majority of young women DO have dense breast tissue. Density is reported on your mammogram report, but often only on the report that goes to the physician, not the "layperson letter" that you would receive. Several states have either passed legislation or have legislation pending that would require mammogram facilities to inform women of their breast density. It is reasonable to ASK your physician or mammographer about your breast density so that you are informed. Depending on your risk factors, additional testing such as ultrasound and MRI might be recommended, but they are currently not recommended for all women with dense breast tissue. However, this field is changing, so stay tuned!

Breast density is something that we as radiologists are always aware of. We always mention in our mammography reports whether the breasts are very dense, moderately so, or not very dense. There are actually 4 categories. The problem is that the information is not always communicated to the patients. We are required by MQSA to provide every patient with the results of their mammogram in writing. Some folks mail these results while others, like myself, usually provide it to the patient when she has completed her exam. We are now attempting to include information about density in those results. Our mammography technologists will answer any questions that the patient may have, and frequently I will also speak with them myself. I don't really have an opinion about whether legislation is the way to handle this.