Prior to diagnosis, a biopsy is usually performed to confirm the presence of cancer cells in the breast. Once a formal diagnosis has been made, other tests are typically performed on the tissue obtained by the biopsy to determine whether the tumor is hormone receptor positive or negative.
If the tumor is hormone receptor positive, it means the breast cancer relies on the hormones estrogen and progesterone to grow. Treatments called hormone therapies are typically used in hormone-positive breast cancers because these treatments work to block the cancer cells from using estrogen and progesterone.
There are several types of hormone therapy that are used to treat breast cancer:
Used for more than 30 years to treat breast cancer, tamoxifen is given as a pill and works by blocking the activity of estrogen. It is given to women who are diagnosed with early-stage breast cancer as well as those who have metastatic breast cancer, meaning the breast cancer has spread to other parts of the body. Research also has demonstrated that tamoxifen helps prevent the recurrence of breast cancer and also helps to prevent breast cancer in women who are at high-risk of developing breast cancer.
Given by injection, these types of drugs include therapies such as leuprolide and goserelin, which are given to prevent the ovaries from making estrogen.
Typically given in women who have already gone through menopause, aromatase inhibitors prevent the body from making estradiol, a form of estrogen. Anastrazole, exemestane and letrozole are all types of aromatase inhibitors used to treat breast cancer.
Breast Cancer Effects