Some lifestyle and behavior factors can influence mammographic breast density (MBD). A recent review, published in The Oncologist, described a variety of associations between MBD, patient characteristics, and breast cancer risk.
In this review, Sara P. Lester, MD, of Mayo Clinic in Rochester, Minnesota, and colleagues explained that MBD is both a risk factor for breast cancer and a characteristic that may obscure lesions on mammograms, leading to additional testing and potentially later diagnoses, as well as other impacts.
MBD represents the level of breast tissue characterized by epithelial and stromal features, in contrast to the level of fatty tissue, which is less dense. Denser tissue elements appear white and show greater radiographic opacity on mammograms, whereas fatty tissue appears darker and more radiographically transparent because it is less able to absorb x-rays, explained Dr Lester and colleagues.
Additionally, MBD can change over a person’s lifetime; it also varies with different physical characteristics, lifestyle factors, and reproductive history. Hormonal status, for example, can affect glandular or ductal changes in breast tissue, in addition to fatty deposition with age. Because menopausal hormone therapy can be associated with increased MBD, women may need to be advised on the relationship between breast density and mammography if considering this therapeutic approach, explained the investigators.
Some physical attributes or lifestyle factors that may show relationships to changes in MBD are modifiable, eg, physical activity, diet, smoking, body mass index, alcohol use. Relationships between these and MBD, in addition to breast cancer risk, vary.
Physical activity and eating a Mediterranean-style diet are associated with lower breast cancer risk; however, they appear to have little effect on MBD. Smoking and greater body mass index are linked to increased risk of breast cancer, but are associated with lower MBD. Alcohol use, like menopausal hormone therapy, is associated with greater MBD; both are risk factors for breast cancer. But effects of caffeine intake and vitamin supplementation on MBD are not well understood, the authors indicated.
Possible benefits of reducing MBD through modifying lifestyle and behavior factors regard its potential to mask breast lesions that have similar appearance on a mammogram. “Reducing MBD helps to decrease the masking effect, thereby improving the sensitivity of mammograms and facilitating an earlier diagnosis,” the investigators noted.
Lester SP, Kaur AS, Vegunta S. Association between lifestyle changes, mammographic breast density, and breast cancer. Oncologist. Published online May 10, 2022. doi:10.1093/oncolo/oyac084