estrogen receptor–positive

Definition of estrogen receptor positive

estrogen receptor positive

(ES-truh-jin reh-SEP-ter PAH-zih-tiv)
Describes cells that have a protein that binds to the hormone estrogen. Cancer cells that are estrogen receptor positive may need estrogen to grow. These cells may stop growing or die when treated with substances that block the binding and actions of estrogen. Also called ER positive.

Source: NCI Dictionary of Cancer Terms