Hormones are chemicals released by glands, such as the testes, pancreas, ovaries, and the thymus. All multicellular organisms release hormones.
In humans, they are transported in the blood. Once the hormones arrive at the intended cell-group or tissue, they activate signal transduction mechanisms, whose purpose it is to provoke specific responses.
For example, when the suprarenal glands release adrenalin, the heart’s response is to beat faster, pumping more blood and oxygen through the body.
Hormones promote cancerous cell division in certain cases, while inhibiting it in others. Some hormones can even kill cancer cells. If hormones are stimulating cancer growth, then hormonal therapy may involve taking medications that impair hormone activity. If hormones are killing cancer cells or hindering cancer cell growth, then hormonal therapy may involve taking medications that trigger hormone activity.
How Does Hormonal Therapy Work?
To determine the potential effectiveness of hormonal therapy, your physician may recommend a hormone receptor test. This test measures the amount of hormone receptors in cancer cells. If, for example, a sample of cancer cells contains large amounts of estrogen receptors, then estrogen is probably stimulating cancer growth.
When high levels of hormone receptors are present, the test results are considered positive. Negative results indicate that hormones are not stimulating the growth of cancer cells.
If a hormone receptor test yields positive results, hormonal therapy is often employed using one of the following modalities:
- Cancer cells are treated with medications that prevent them from receiving the hormones that are stimulating malignant cell growth.
- The gland or glands responsible for producing cancer-stimulating hormones are treated with medications that inhibit them from producing the harmful hormone.
- If medication alone cannot inhibit hormone production or reception, then surgery is often employed. Typically, this surgery involves the complete or partial removal of the hormone-producing gland. The ovaries, for example, are commonly removed to treat certain types of uterine cancer.
The Focus of Hormonal Therapy
Hormonal therapy is typically prescribed as an adjuvant treatment option. This means that the therapy is employed in conjunction with other cancer treatment modalities. Some cancers, specifically breast cancer, may be treated with hormonal therapy exclusively.
In many cases, hormonal therapy is prescribed before the primary cancer treatment. The purpose of this prescription is to kill as many of the cancer cells as possible, making the primary treatment more effective. This is known as neoadjuvant hormonal therapy.
Hormonal Therapy Medications
These medications are commonly prescribed to inhibit the growth, spread, and invasive behaviors of cancer cells.
- Tamoxifen (Nolvadex®): This medication is used to treat breast cancer. It does not inhibit estrogen production. Instead, it impairs the malignant cells’ ability to receive the estrogen.
- Anastrozole (Arimidex®) and Letrozole (Femara®): These two medications, recently approved by the Food and Drug Administration (FDA), inhibit estrogen production. These drugs are used primarily to treat breast cancer, but may also be used to treat various other cancers that are stimulated by estrogen production.
- Lupron, Zoladex, Eligard, Viadur, Trelstar, and Vantas: These drugs are frequently used to treat prostate cancer by impairing the testes’ ability to produce testosterone.
- Nilandrone, Casodex, and Eulixin: These medications inhibit the ability of certain cancer cells to receive the testosterone hormone.
Talk to your oncologist about the hormonal therapy medications available for your cancer.
Side Effects of Hormonal Therapy
Each patient’s hormonal therapy experience is unique. Not everyone will experience the same side effects. In some cases, side effects may be completely absent, whereas in others they can be severe.
BREAST CANCER HORMONAL THERAPY SIDE EFFECTS
- Nausea and vomiting
- Hot flashes
- Skin rashes
- Loss of appetite
- Vaginal drying and/or itching
- Weight gain
- Irregular menstruation
- Vaginal spotting
PROSTATE CANCER HORMONAL THERAPY SIDE EFFECTS
- Male breast growth
- Hot flashes
- Lack of sexual desire