good result to treatment

Estrogen receptor status really refers to whether or not a cancer cell has the estrogen receptor on it.

Estrogen is just a protein that's found in the female body. The way they interact is that estrogen would be circulating in the bloodstream, and when it encounters its own receptor, it will bind to it. In breast cancer cells that have the estrogen receptor, otherwise known as estrogen receptor-positive, that leads to the growth of the breast cancer cells. So in a sense, the estrogen binds to the estrogen receptor and acts, in a sense, like food for the breast cancer cell. It stimulates it to grow.

Estrogen receptor-negative tumors do not possess the estrogen receptor, which is simply a protein on their surface, and thus, we believe, do not depend on the female hormone estrogen for their growth.