Estrogen Receptor Positive

Estrogen receptor positive (ER-positive) refers to certain breast cancers that have cells with receptors for the hormone estrogen. These receptors allow estrogen to bind and stimulate cancer growth. If a tumor is ER-positive, it means hormone therapy targeting these receptors can be effective in slowing or stopping the cancer. This classification helps doctors determine the most appropriate treatment strategy and usually indicates a better prognosis compared to tumors without estrogen receptors. Essentially, ER-positive cancers rely on estrogen signals for growth, and therapies can be designed to block or reduce these signals.