Low-level chronic inflammation caused by overexpression of the cytokine CCL2 was found to increase breast tissue density and elevate breast cancer risk in animal studies, researchers reported in the journal Breast Cancer Research.1

“Overexpression of CCL2 in the mammary epithelium resulted in an increased number of macrophages, increased density of stroma and collagen, and elevated mRNA encoding matrix remodelling enzymes” compared to controls, reported senior study author Wendy V. Ingman, PhD, of the University of Adelaide, South Australia, and colleagues.

Studying human breast tissue, epithelial-cell CCL2 abundance was higher in breast tissue that mammography revealed to be high-density, compared to low-density breast tissue.

Anti-inflammatory drugs such as aspirin might reduce the risk of breast cancer but their long-term prophylactic use can be associated with adverse effects. The new findings suggest that clinical studies of anti-inflammatory agents’ cancer-prevention value among women with dense breast tissue might be warranted.

Reference

1. Sun X, Glynn DJ, Hodson LJ, et al. CCL2-driven inflammation increases mammary gland stromal density and cancer susceptibility in a transgenic mouse model. Breast Cancer Res. 2017;19:4. doi: 10.1186/s13058-016-0796-z