Hormones are chemicals made by glands, such as the ovaries and testicles. Hormones help some types of cancer cells grow, such as breast cancer and prostate cancer. In other cases, hormones can kill cancer cells, slow their growth, or stop them from growing. Hormone therapy as a cancer treatment may involve taking medicines 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 making the hormones.

Your doctor may advise a hormone receptor test to help determine treatment options and to help learn more about the tumor. This test can help to predict how the cells will react to hormones.

The hormone receptor test measures the amount of certain proteins (called hormone receptors) in cancer tissue. Hormones (such as estrogen and progesterone) can attach to these proteins. If the test is positive, it means the hormone is probably helping the cancer cells grow. In this case, hormone therapy may be given to block the way the hormone works and help keep them 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 cancer treatments may be given. Always discuss the results of the hormone receptor test with your doctor.

If the test shows that the hormones are affecting your cancer, the cancer may be treated in one of following ways:

• Treating cancer cells to keep them from getting the hormones they need to grow

• Treating the glands that produce hormones to stop them from making hormones

• Surgery to remove glands that make the hormones, such as the ovaries that make estrogen, or the testicles that make testosterone

The type of hormone therapy you get depends on many factors, such as the type and size of your tumor, your age, the presence of hormone receptors on the tumor, and other factors.

Your doctor may prescribe hormone therapies before some cancer treatments or after other cancer treatments. If hormone therapy is given before the primary treatment, it is called neoadjuvant treatment. Neoadjuvant treatments help 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, people 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 relieving the painful 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.