Hormonal Therapy: Managing Side Effects in Women
Hormones are chemicals the body naturally produces to control the growth and activity
of normal cells. 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
In general, there are 2 different approaches to hormonal therapy:
Surgical. Removal of an organ in the body that produces the hormone or hormones that stimulate
cancer growth. For example, in men, the testes, which produce testosterone, can be
removed with a procedure called an orchiectomy, to slow the growth of some prostate
Medical. Medicines are used to block the hormones that stimulate cancer growth. For example,
the medicine tamoxifen helps prevent estrogen from stimulating breast 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 is 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 (metastasized)
to other parts of the body. It is also used on occasion 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
Types of hormonal therapies
There are a variety of hormonal therapies available for breast cancer. Each type works
a bit differently, but all have the same goal of starving the tumor of estrogen:
Selective estrogen receptor modulators (SERMs). 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.
Aromatase inhibitors. These drugs are used in older women who have been through menopause.
Although the ovaries of these women no longer produce large amounts of estrogen, male
hormones (androgens) do circulate in the blood and 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 antagonist. A newer class of hormonal therapy drugs is the estrogen
receptor (ER) antagonist. One example is fulvestrant, which is given by a monthly
injection into the muscle. Like SERMs, ER antagonists 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
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 the symptoms 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
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 is 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
Clonidine, normally used to lower high blood pressure, 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.
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 can be used as needed to keep the
vagina moist. Water-soluble lubricants or any vaginal moisturizers can be used before
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 yeast infections, but a woman should contact her gynecologist
for symptoms that do not go away.
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, medications,
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, 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 alfa or
blood transfusions, may be prescribed
Nausea and vomiting
This side effect is less common with hormonal therapy than it is with chemotherapy.
Nausea often goes away on its own. Women can help manage symptoms by eating bland
foods, such as crackers, toast, and cereal, and drinking lots of fluids–-6 to 8 glasses
of liquids daily, such as water, broth, or electrolyte solutions. The doctor or nurse
may recommend antinausea medicines or antianxiety medications that prevent or treat
nausea or vomiting. If dehydration occurs, intravenous fluids may be needed.
Diarrhea is a less common side effect of hormone therapy. Dietary measures, such as
eating a bland diet and avoiding foods such as dairy products and spicy foods, can
help reduce symptoms. Medicines such as loperamide and diphenoxylate can be used to
Constipation is a less common side effect of hormone therapy. Daily exercise, eating
foods high in fiber (such as uncooked fruits and vegetables and whole grain breads
and cereals) and drinking lots of liquids—6 to 8 glasses a day—can help ease symptoms.
If these measures do not work, medicines, such as a stool softener or laxative, may
A daily exercise routine of 20 to 30 minutes per day and a weight management program
can be helpful. Eating foods low in fat, such as fruits and vegetables, is a good
Nervousness, depression, and anxiety are some of the symptoms that women may experience.
It is natural to experience strong emotions in response to a diagnosis of breast cancer.
These may become stronger when a woman receives hormonal therapy. Relaxation, meditation,
and yoga may be useful in controlling mood swings. Exercise may help boost mood and
relieve anxiety. Support groups and professional counselors may be helpful for some
women. Antidepressants may be prescribed.
Pain, including pain in joints, back, and bones
For mild to moderate pain, over-the-counter pain medication can help alleviate pain
in various parts of the body, such as the joints or back. Pain felt at an injection
site can be treated with warm or cold compresses. A topical anesthetic cream may also
Certain hormonal therapies, such as the aromatase inhibitor anastrozole, can increase
coughing symptoms. Women should try to drink at least 8 glasses of fluid a day to
keep the lining of the breathing tube moist. Using a humidifier to increase the moisture
in the air is also a good idea. Medicines, such as dextromethorphan, benzonatate,
and guaifenesin, may be used to stop or control coughing.
Osteoporosis is a disorder in which bones become porous and break more easily. Women
who have gone through menopause have a higher risk of bone loss. Some hormone therapies,
such as tamoxifen in some case, may lower bone loss in postmenopausal women. Other
hormone therapies may not prevent or modify a woman's risk of getting osteoporosis.
For this reason, postmenopausal women with breast cancer should have a bone mineral
analysis to determine if a preventive therapy should be used.
Women treated with hormonal therapy should have routine screenings (bone density scans)
for osteoporosis. The following suggestions are recommended for people at risk:
Take calcium and vitamin D supplements
Get regular physical activity, including weight-bearing exercises that put stress
on bones, such as jogging, stair climbing, dancing, and resistance exercises, such
as weight lifting.
Modify alcohol intake
Medicines that prevent bone loss include the bisphosphonates risedronate, zoledronic
acid, alendronate, denosumab, and calcitonin. Women should talk to their doctor about
which medicines, if any, would be best for them.
Rare but serious side effects
Although most side effects of hormonal therapy are not life-threatening, in very rare
cases, tamoxifen can raise a woman's chances of getting endometrial cancer. Women
taking tamoxifen should report any unusual vaginal discharge, vaginal bleeding, menstrual
irregularities, or pain or pressure in the lower abdomen to their doctor or nurse.
Annual pelvic examinations to look for signs of cancer are also recommended.
Some hormonal therapies carry a slight risk of blood clots forming in the deep blood
vessels of the legs and groin. Clots can break off and spread to the lungs. Blood
clots stop the flow of blood and can cause serious medical problems. Signs of a blood
clot in the lungs include sudden chest pain, shortness of breath, or coughing up blood.
Symptoms of a blood clot in the legs include pain, swelling, or tenderness in the
groin or legs. Women should let their doctor know if they have a history of blood
clots. They should also report any of these symptoms to the doctor or nurse as soon
Effects on the eye
Tamoxifen can cause cataracts or changes to the parts of the eye called the cornea
and retina. Women should report any vision changes—including an inability to tell
the difference between colors—to their healthcare provider.
Tamoxifen increases a woman's chance of having a stroke. Symptoms of stroke include
weakness, sudden severe headache, slurred speech, trouble with seeing in one or both
eyes, difficulty walking or talking, or numbness of the face, arm, or leg. Women should
immediately report these symptoms to their doctor.