Dense breast tissue has been established as a risk factor for breast cancer.
The presence of dense breast tissue identified on a mammogram is a two-fold concern: simply having dense breasts increases your chance of developing breast cancer compared with women with non-dense breasts. But in addition, dense breast tissue may obscure breast cancer because both dense tissue and breast cancer appear white on a mammogram. As breast density increases, the sensitivity of mammography decreases (meaning it is more difficult to identify a suspicious finding in the midst of dense tissue which may hide it). Due to this, other screening options have been offered to women with dense tissue, ultrasound primarily being the modality of choice.
With about 43% of screening-aged women having dense breast tissue, a large percentage of the population needs additional screening.
Several studies have evaluated the performance of supplemental screening ultrasound in women with dense breast tissue, showing improved cancer detection for this population. It is important to note that many of these studies included women with other risk factors, in addition to having dense tissue, such as a family history of breast cancer or personal history of breast cancer. The benefit of ultrasound in women at average risk (i.e., with no known risk factors) has remained unclear.
A recent large study evaluated asymptomatic women aged 40 to 49 regardless of their breast density having supplemental screening ultrasound adjunctive to mammography. In their analysis, researchers found supplemental ultrasound was associated with increased sensitivity – with the potential to improve detection of early-stage and invasive breast cancers across both dense and non-dense breasts.
These findings confirm the benefit of performing screening ultrasound for women with dense breast tissue and bring up the interesting point of performing supplemental ultrasound for women at average risk.
If you have heterogeneously dense or extremely dense tissue, your mammogram result letter will indicate that and recommend that you talk to your referring health care provider about your breast cancer risk and whether you may benefit from additional testing. If you and your primary care physician wish to have a screening ultrasound because your breast tissue is dense, Elizabeth Wende Breast Care (EWBC) can provide that service at any of our seven locations.