Some breast cancers express female hormones, called estrogen and progesterone. These hormones attach to hormone receptors on the surface of the breast cancer and cause the cancer to grow. Mercy’s pathologists assess all breast tumors for the expression of these receptors. The tumors are then classified as "hormone positive" or "hormone negative."
Hormone positive breast tumors can be treated with drugs (such as Tamoxifen) or aromatase inhibitors (such as Anastrozole). Tamoxifen works by attaching to the hormone receptor and preventing the estrogen hormone from attaching to it. The aromatase inhibitors lower the levels of estrogen in the body, so that the estrogen is not readily available to the cancer cell.
Tamoxifen and the aromatase inhibitors can be used to treat early, locally advanced or metastatic (widely spread) breast cancer. Your medical oncologist can review the risk and benefits of these medications with you if your tumor is hormone positive.