Yes. There is a 1.8-fold higher risk of cancer in the opposite breast among women with dense breasts , but density and associated risk can be reduced with treatment. A 10% decrease of mammographic density or more within the first two years after an original diagnosis, as a result of treatment, is associated with a significantly reduced risk of cancer in the opposite breast (known as contralateral breast cancer) . This potential new risk predictor can thus contribute to decision-making in follow-up treatment – particularly the continuation of a chemoprevention drug, like tamoxifen or aromatase inhibitors, which reduce breast density in some women .
1. Raghavendra A, Sinha AK, Le-Petross HT, et al. Mammographic breast density is associated with the development of contralateral breast cancer. Cancer 2017; 123:1935-1940
2. Sandberg ME, Li J, Hall P, et al. Change of mammographic density predicts the risk of contralateral breast cancer: a case-control study. Breast Cancer Res 2013; 15:R57
3. Engmann NJ, Scott CG, Jensen MR, et al. Longitudinal changes in volumetric breast density with Tamoxifen and aromatase inhibitors. Cancer Epidemiol Biomarkers Prev 2017; 26:930-937