Hormone therapy (HT) is used to treat certain cancers that depend on hormones to grow and spread. Patients who undergo this treatment sometimes have surgery or take medications that reduce the levels of certain hormones, such as estrogen (in women) and testosterone (in men). In other cases, patients may take drugs that prevent cancers from receiving the hormones they need to grow.

Hormones are substances produced by one tissue and moved by the bloodstream to another to influence a physiological activity, such as growth or metabolism. They occur naturally in the body, but can also be made synthetically. In some cases, hormone therapy consists of taking medications that suppress the production or interfere with the action of certain hormones. In other cases, surgery may be performed to remove the gland that produces the hormone.

Hormone therapy is used to treat several types of cancer, including:

• Breast cancer
• Ovarian cancer
• Uterine cancer
• Prostate cancer

In most cases, hormone therapy is not a first-line cancer treatment. Instead, it is used in combination with other treatments such as chemotherapy, radiation therapy or after surgery. Hormone therapy sometimes causes side effects, including temporary or permanent infertility. In addition, some cancers become resistant to hormone therapy and begin to grow again after a period of time. Patients with hormone-sensitive cancers should talk with their physician or oncologist about the potential benefits and risks of using a hormone therapy treatment regimen.