Mount Sinai researchers have discovered that normal immune cells called macrophages, which reside in healthy breast tissue surrounding milk ducts, play a major role in helping early breast cancer cells leave the breast for other parts of the body, potentially creating metastasis before a tumor has even developed, according to a study published in Nature Communications. The macrophages play a role in mammary gland development by regulating how milk ducts branch out through breast tissue. Many studies have also proven the importance of macrophages in metastasis, but until now, only in models of advanced large tumors.

See original article at: https://www.sciencedaily.com/releases/2018/01/180102103323.htm