-- Question:What does it mean if my breast cancer is hormone receptor-positive or negative?
Answer: Hormone receptor-positivity or negativity refers to the ability of the cancer cells to respond to estrogen or progesterone. Normal breast tissue does respond to estrogen, which is why breasts grow in young women when they turn from girls into women, because the estrogen that is produced by the ovary actually make the breast tissue grow. Well, some breast cancers also can respond to estrogen in terms of their growth, and this is particularly so in older women with breast cancer -- post-menopausal women. If we see that the cancer likes estrogen and needs estrogen to grow -- and you can tell this by looking at something called the 'estrogen receptor,' which is a protein in the cell that attaches to estrogen -- or progesterone receptor; if we see those receptors in the cell then we know that this tumor has some element of dependence on estrogen, and we can use that information in planning therapies, such as tamoxifen or a class of drugs called the aromatase inhibitors, that deprive the cancer cell of estrogen and therefore inhibits its growth, if it is estrogen responsive.