Hormones are chemicals produced by glands, such as the ovaries and testicles. Hormones help some types of cancer cells to grow, such as breast cancer and prostate cancer. In other cases, hormones can kill cancer cells, make cancer cells grow more slowly, or stop them from growing. Hormone therapy as a cancer treatment may involve taking medications that interfere with the activity of the hormone or stop the production of the hormones. Hormone therapy may involve surgically removing a gland that is producing the hormones.
A physician may recommend a hormone receptor test to help determine treatment options and to help learn more about the tumor. This test can help to predict whether the cancer cells are sensitive to hormones.
The hormone receptor test measures the amount of certain proteins (called hormone receptors) in cancer tissue. Hormones (such as estrogen and progesterone that naturally occur in the body) can attach to these proteins. If the test is positive, it is indicating that the hormone is probably helping the cancer cells to grow. In this case, hormone therapy may be given to block the way the hormone works and help keep the hormone away from the cancer cells (hormone receptors). If the test is negative, the hormone does not affect the growth of the cancer cells, and other effective cancer treatments may be given.
If the test indicates that the hormones are affecting the cancer, the cancer may be treated in one of following ways:
- Treating cancer cells to keep them from receiving the hormones they need to grow.
- Treating the glands that produce hormones to keep them from making hormones.
- Surgery to remove hormone producing glands, such as the ovaries that produce estrogen or the testicles that produce testosterone.
The type of hormone therapy a person receives depends upon many factors, such as the type and size of the tumor, the age of the person, the presence of hormone receptors on the tumor, and other factors.
A physician may prescribe hormone therapies before some cancer treatments or after other cancer treatments. If hormone therapy is given as a first step to shrink a tumor before the main treatment, it is called neoadjuvant treatment. Neoadjuvant treatments help to kill cancer cells and contribute to the effectiveness of the primary therapy. If hormone therapy is given after the primary cancer treatment, it is called adjuvant treatment. Adjuvant therapy is given to improve the chance of a cure.
With some cancers, patients may be given hormone therapy as soon as cancer is diagnosed, and before any other treatment. It may shrink a tumor or it may halt the advance of the disease. And in some cancer, such as prostate cancer, it is helpful in alleviating the painful and distressing symptoms of advanced disease. The National Cancer Institute (NCI) states that although hormone therapy cannot cure prostate cancer, it will usually shrink or halt the advance of disease, often for years.