Hormone Therapies

Some breast cancer cells grow with the help of estrogen and/or progesterone (female hormones that are produced in the body). When these hormones attach to special proteins called hormone receptors, the cancer cells with these receptors grow.

Hormone therapies can stop this growth by preventing the cancer cells from getting the hormones they need to grow. They can do this in several ways. Some hormone therapies, like the drug tamoxifen, attach to the receptor on the surface of the cancer cell and block estrogen from attaching to the receptor. Other therapies, like aromatase inhibitors, lower the level of estrogen in the body so that the cancer cells cannot get the estrogen they need. Figures 5.4 and 5.5 list the common hormone therapies for early, locally advanced and metastatic breast cancer. These figures do not include rarely used drugs or those no longer in use.

Adapted from Table 1. Murphy et al. 1997 [36]

Hormone therapies only work if the tumor cells are "hormone receptor-positive” (estrogen receptor-positive and/or progesterone receptor-positive). For this reason, all tumors are tested for these markers. A pathologist determines the receptor status by testing the tumor tissue that is removed during a biopsy. For more on hormone receptor status, see the Diagnosis  section.

Adjuvant Therapy Treatment - videos

Updated 08/25/09

	Tamoxifen
	Aromatase Inhibitors