Expression data from primary human mammary fibroblasts purified from disease-free women of low and high mammographic density

Although high mammographic density (MD) is considered one of the strongest risk factors for invasive breast cancer, the genes involved in modulating this clinical feature are unknown. Histologically, areas of high MD are associated with low adipocyte content and high matrix content, both stromal phenotypes. We hypothesized that fibroblasts purified from low and high MD tissues would show gene expression differences responsible for these histologic differences. Fibroblasts were purified from disease-free breast tissue from 6 women with low MD (MD quartile 2) and 7 women with high MD (MD quartile 4). The fibroblasts were cultured for 3 to 6 passages before cells pellets were collected for this study.