Following genetic tests such as Oncotype DX, it may be determined that a patient’s specific type of cancer cells have important hormone receptors on their surface that make them susceptible to hormone therapy in addition to other types of treatment. Hormone therapy is unique from chemotherapy and radiation therapy in that it may be used as a preventative measure in addition to a treatment option for patients that have had or may be at higher risk for breast cancer. The main hormone targeted in this therapy is estrogen, which affects cells in the breasts and causes them to develop during puberty. This is a natural process in the female body, but after the development of hormone receptor positive cancer this hormone can have a negative effect on the body by causing the development of more cancer cells. There are two ways to prevent this cancer growth through hormone therapy: either by blocking the receptors on the cancer cells and starving them or by stopping the production of more estrogen in the body.
There are a wide range of hormone therapy drugs on the market that may be chosen according to a patient’s age, medical history, and pre-disposition to cancer. One class of drugs is selective estrogen receptor modulators, or SERMs. These drugs can be taken orally to prevent the recurrence of cancer if the patient is a cancer survivor or to prevent the metastasis of cancer in the body if the patient is currently battling the disease. The other type of hormone therapy drug is known as aromatase inhibitors. This drug is useful for postmenopausal women, whose ovaries have lost the ability to produce estrogen and receive their only source of estrogen from the adrenal glands. These inhibitors do just as their name suggests and render aromatase inactive. Aromatase is an enzyme responsible for acting on compounds in the body known as androgens, which are converted into hormones such as estrogen. In other words, aromatase inhibitors accomplish the same task as SERMs by eliminating the source of more estrogen within the patient’s body.