Breast Density and Cancer

Extract

The decrease in the radio-opaque density of mammograms by 6.1% in healthy, lean (body mass index <23) women, 30–65 years of age, who were fed a low-fat diet for 2 years ( 1 ) suggests that environmental factors modulate mammary parenchymal metabolism. However, it is unclear whether these findings are applicable to the individual woman in the detection of breast cancer.

In the Dom study of 23 311 postmenopausal Dutch women, which investigated the radiologic aspects of breast structure, de Waard ( 2 ) concluded that, from puberty on, breast abnormalities increase unless counteracted by pregnancy and that dysplasia in women with a pregnancy after 35 years of age involved luteal insufficiency. Furthermore, de Waard et al. ( 3 ) reported that a family history of breast cancer increased the positivity rate of mammary screening (relative risk [RR] = 2.2 positive/negative).

While the accuracy of screening varies among studies, it should be noted that 1) only 15% of the volume of breasts of premenopausal women consists of epidermal cells, 2) mammary dysplasia is not associated with estrogen receptor concentration ( 4 ), and 3) breast cancer develops in a large number of women who do not have radiologic abnormalities ( 5 ).