For some cancer patients, hormonal therapy involves the use of medications that interfere with or stop production of hormones that help some types of cancer cells, particularly breast cancer and prostate cancer, grow. In other cases, as a hormonal therapy treatment a surgeon may remove the gland producing these hormones.
For individuals with breast cancer, doctors may begin with a hormone receptor test of the tumor. This test can help them learn more about the tumor and how to treat it, as well as to predict whether or not these cells are sensitive to hormones. This test works by measuring the amount of proteins called hormone receptors in cancerous tissue. A positive test indicates that naturally occurring hormones such as progesterone and estrogen have attached to the cancer cells and are helping them grow. A negative test means the hormone is not affecting the cancer’s growth, and other cancer treatments may prove effective.
If there’s a positive test, treatment will follow one of three paths: the cancer cells are treated to prevent them from receiving the hormones that are helping them grow; the glands that produce the hormones are treated; or a surgeon will removes these problematic glands, such as removing the ovaries (which produce estrogen) or testicles (which produce testosterone).
Hormonal therapy given before surgery is called neoadjuvant therapy; it is used to help kill cancer cells, shrink tumors, and make eventual surgery easier in regard to removing the tumor. If the hormonal therapy is performed after surgery, is it called adjuvant therapy, and it’s used to improve the patient’s chances of being cured.
Sometimes, therapy begins as soon as the cancer is diagnosed, before any other treatment. In some types of cancer, such as prostate cancer, hormonal therapy can be helpful in alleviating the symptoms associated with advanced stages of the disease—hormonal therapy cannot cure advanced prostate cancer, but it can shrink tumors or slow the disease’s progression.
For women (and men) with breast cancer, a drug called tamoxifen is commonly used to block the effects of estrogen on malignant cancer cells, though it does not stop estrogen production. Tamoxifen is currently being studied for its effectiveness on other types of cancer as well. Newer medications called aromatase inhibitors are used to treat advanced breast cancer or prevent a recurrence of breast cancer in postmenopausal women by preventing the production of estrogen. In addition, the FDA has approved the use of a drug called raloxifene for postmenopausal women at high risk of breast cancer.
For men with prostate cancer, hormonal therapy is used to stop the production of testosterone, which stimulates prostate cancer to grow. Hormonal therapy can cause tumors to shrink and prostate-specific antigen levels to decrease.