Mammographic breast density and breast cancer risk

Women who have a breast density of 75 percent or higher on a mammogram have a risk of breast cancer that is four to five times greater than that of women with little or no density, making mammographic breast density one of the strongest biomarkers of breast cancer risk.

Mammographic density of the breast compares the amount of the X-ray that appears white to the amount of the X-ray that appears grey. The more white the greater the density. The white area reflects the amount of connective tissue, milk ducts, lobules and fluid in the breast. The grey area reflects the amount of fat in the breast. The research was presented at the American Association for Cancer Research 101st Annual Meeting in April 2010.

Carol J. Fabian, M.D., professor of medicine in the division of clinical oncology and director of the Breast Cancer Prevention Center at the University of Kansas Medical Center stated in an interview reported on Science Daily that "These abstracts strengthen the observation that high breast density is associated with increased risk for breast cancer, and they strengthen the hypothesis that under some conditions, reducing breast density may be associated with reduced risk for breast cancer,"

Increased breast density is a known risk for breast cancer, but having a lower breast density doesn't necessarily mean a low risk of developing breast cancer, according to Fabian. Other risk factors are at play, and mammographic density is one tool to help determine a women's risk.

The supplement N-Acetylcysteine and the drug metformin reduce mammographic breast density in postmenopausal women in this Russian study

In this small but encouraging study 25 postmenopausal women received the drug metformin at 1000mg to 1,500mg a day for 10.5 months on average or they received the supplement NAC (N-Acetylcysteine) at a dosage of 400mg to 600mg a day for the same time period. Metformin reduced mammographic breast density by 5% in 28.5 % of the women and NAC reduced mammographic breast density by 6% in 27.3% of the women.