By M.J. Freidrich, Pure Matters
Hormones can also speed the growth of some types of cancer. For example, the hormones estrogen and progesterone can stimulate the growth of some breast tumors.
Hormonal therapy is used to prevent or block hormones from speeding up the growth of cancer cells. Different forms of hormonal therapy, which is also called hormone therapy or endocrine therapy, are used to treat breast, prostate, and endometrial cancers.
In general, there are two different approaches to hormonal therapy:
- Surgical, in which an organ in the body that produces the hormone or hormones that stimulate cancer growth is removed. For example, the ovaries, which produce estrogen, can be removed to slow some breast cancer growth.
- Medical, in which agents are used to block the hormones that stimulate cancer growth. For example, the drug tamoxifen helps prevent estrogen from stimulating prostate cancer growth.
The female hormones estrogen and progesterone promote the growth of some breast tumors. Hormonal therapy may be given to block these hormones from stimulating tumor growth.
Many breast cancer cells have proteins on their surfaces that can bind to estrogen. These proteins are called estrogen receptors. Tumors may also have progesterone receptors that bind to progesterone. When estrogen or progesterone binds to its receptor on the cancer cell, it signals that cell to grow.
Not all breast cancers have estrogen or progesterone receptors. In general, hormonal therapy appears to be more effective in treating breast tumors that have hormone receptors than in treating tumors that do not have these receptors.
Hormonal therapy is used in women with advanced breast cancer that has spread, or metastasized, to other parts of the body. It is also used in women who have been recently diagnosed with a large breast tumor to shrink the cancer before surgery (neoadjuvant therapy) or to prevent cancer from returning after surgery or radiation (adjuvant therapy). In some women, who have a high risk for getting breast cancer, hormonal therapy is used to prevent cancer from developing.
Hormonal therapy, like other types of cancer treatment, has side effects. An overview of hormonal therapies and ways to prevent or minimize these side effects are discussed below
Types of Hormonal Therapies
There are a variety of hormonal therapies are available for breast cancer. Each type works a bit differently, but all have the same goal of starving the tumor of estrogen.
- SERMs. Selective estrogen receptor modulators (SERMs) are antiestrogen drugs that bind to the estrogen receptor. This prevents estrogen from binding to the receptor and stimulating cancer cell growth. SERMs include tamoxifen, toremifene and raloxifene. They are taken as oral tablets. Tamoxifen is the most commonly used SERM.
- Aromatase inhibitors. These drugs are used in older women who have been through menopause. Although their ovaries no longer produce large amounts of estrogen, male hormones (androgens) do circulate in the blood that can be changed into estrogen. An enzyme called aromatase carries out this change. Aromatase inhibitors prevent aromatase from changing androgens into estrogen. Anastrozole, letrozole, and exemestane are examples of aromatase inhibitors. They are taken as oral tablets.
- Estrogen receptor downregulators. A new class of hormonal therapy drugs is the estrogen receptor (ER) downregulator. One example is fulvestrant, which is given by a monthly injection into the muscle. Like SERMs, ER downregulators bind to the estrogen receptor and block estrogen from binding to it. In addition, they also break down the estrogen receptor, lowering the number of receptors in the cell (a process called downregulation).
- Megestrol acetate. This is a progesterone-like drug that may be used in women with advanced breast cancer who do not benefit from tamoxifen.
- Ovarian ablation. The ovaries are the main source of estrogen in women who have not reached menopause. They may be removed by surgery through a procedure called oophorectomy or they may be made inactive by radiation therapy. Removing or inactivating the ovaries causes premature menopause and its symptoms, including hot flashes and vaginal dryness. Loss of bone mass also occurs in menopause. When the ovaries are removed, a large amount of bone can be lost in a short time, which can lead to osteoporosis if it is not treated.
Side Effects Of Hormonal Therapy And Ways To Manage Them
The side effects of hormonal therapy tend to be less severe than those caused by chemotherapy. In fact, some women experience few symptoms or have side effects that get better with time. But when side effects do arise, it is important for women to report all symptoms, even those that are minor, to a nurse or doctor. Hormonal therapy is often taken for long periods of time and symptoms can last throughout treatment if they are not treated. Women should also always talk to their doctor about any alternative remedies they might want to try. Some alternative remedies can interfere with treatment.
Below are some ways to cope with some of the side effects of hormonal therapy.
More Common Side Effects
Hot flashes. A hot flash, also called a hot flush, with or without sweating, is a sudden rush of warmth to the face, neck, upper chest, and back that can last for a few seconds to an hour or more. This side effect is quite common with hormonal therapy. Some women experience mild symptoms while others have more severe effects. In many cases, hot flashes stop when hormonal treatment stops. Some women report that hot flashes last for years after treatment is finished.
The following are some treatment options for managing hot flashes. Not all have been scientifically tested:
- Megestrol acetate (Megace), a form of progesterone called progestin that seems to be effective in lowering hot flash severity, but has some side effects, including breast tenderness, irregular vaginal bleeding, mood changes, and bloating.
- Antidepressants, such as venlafaxine (Effexor), given in doses smaller than those given for depression.
- Medroxyprogesterone acetate (Depo-Provera)
- Clonidine (Catapres), normally used to lower high blood pressure. Comes in a patch. May be no better than a placebo, or dummy pill. Side effects include dry mouth, dizziness, drowsiness, and sleep difficulties.
- Phytoestrogens are estrogens that come from plants. Soy products and some herbs contain phytoestrogens. Although raising the amount of phytoestrogens in the diet is commonly recommended to lessen the severity of hot flashes, studies have shown conflicting results about their effectiveness.
- Vitamin E, undergoing evaluation but overall effects seem to be small.
- Relaxation training
- Dietary changes – avoid caffeine, alcohol, and spicy foods.
- Clothing – wear absorbent cotton clothing in layers that can be easily removed.
- Use sprays or moist wipes to help lower skin temperature.
Vaginal dryness and other vaginal issues. Vaginal dryness and/or discharge can be bothersome. Vaginal moisturizers and lubricants can help with this symptom. Vaginal moisturizers, such as Replens, Gyne-Moistrin, and Lubrin, can be used as needed to keep the vagina moist. Water-soluble lubricants, such as KY Jelly and Astroglide or any vaginal moisturizers, can be used before sexual activity. Applying vitamin E to the area can lessen irritation and burning.
In addition to vaginal dryness, women may also experience vaginal thinning and difficult or painful intercourse. Lubricants can help with some of these problems, as well.
Vaginal infections may also occur more frequently. Over the counter antifungal creams can provide relief for infections, but a woman should contact her gynecologist for symptoms that do not go away.
Fatigue. A common problem in women with cancer is fatigue or a lack of energy. Many things can cause fatigue, such as anemia, depression, pain, poor nutrition, medication, and inadequate sleep. Some ways to prevent fatigue include:
- Go to bed at a regular time
- Take short "power" naps during the day
- Engage in an exercise routine, with doctor's supervision. For example work out a moderate, low-intensity exercise such as walking 10 to 30 minutes a day.
- Eat healthy foods and drink fluids
- If anemia is contributing to fatigue, blood growth stimulators such as epoetin alpha (Procrit) or blood transfusions may be prescribed