Unlocking Breast Cancer Estrogen is a hormone that plays a critical role in the development and metabolism of the breast, among other organs. The breast contains receptors for hormones such as estrogen.
Receptors resemble locks into which only certain keys can fit.
Both the body's own natural estrogen as well as foreign materials, called xenoestrogens, can fit into these locks, or receptors, and alter how much and what types of estrogen the body produces. Once xenoestrogens reach the inside of a cell, they may promote cancer-causing behaviors in a number of ways.