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Chemotherapy for breast cancerBy Mayo Clinic staff
Original Article: http://www.mayoclinic.com/health/chemotherapy-for-breast-cancer/MY01368
Chemotherapy for breast cancer uses powerful drugs to target and destroy fast-growing breast cancer cells. Chemotherapy for breast cancer is frequently used along with other treatments for breast cancer, such as surgery. But chemotherapy for breast cancer also may be used as the primary treatment, when surgery isn't an option.
Various chemotherapy drugs are available to treat breast cancer. Breast cancer chemotherapy drugs may be used individually or in combination to increase the effectiveness of the treatment.
Chemotherapy for breast cancer can help you live longer and reduce your chances of having the cancer come back (recur). But chemotherapy for breast cancer also carries a risk of side effects — some temporary and mild, others more serious or permanent. Your doctor can help you decide whether chemotherapy for breast cancer is a good choice for you.
Why it's done
Chemotherapy for breast cancer may be given in the following situations:
Chemotherapy after surgery for early breast cancer
After surgical removal of a tumor from a breast, your doctor may recommend chemotherapy to destroy any remaining cancer and to reduce your risk of the cancer recurring. This is known as adjuvant chemotherapy.
Your doctor may recommend adjuvant chemotherapy if you have a high risk of the cancer recurring or spreading to other parts of your body (metastasizing), even if there is no evidence of any cancer left after surgery. You may be at higher risk of metastasis if cancer cells are found in lymph nodes near the breast with the tumor. It's important to talk to your doctor about how much the chemotherapy will reduce your chance of the cancer coming back, and whether this decrease in risk is worth the side effects of the chemotherapy. Also discuss with your doctor other possible alternatives, such as hormone-blocking therapy, that might be effective in your situation.
Chemotherapy before surgery for early breast cancer
Some women with breast cancer receive chemotherapy before surgery (neoadjuvant therapy), generally to shrink large tumors and allow the surgeon the best possible chance of completely removing the tumor. In some cases, neoadjuvant therapy also allows the surgeon to remove only the tumor, rather than the entire breast.
Chemotherapy as the primary treatment for advanced breast cancer
If breast cancer has spread to other parts of your body and surgery isn't an option, chemotherapy can be used as the primary treatment. It also may be used in conjunction with hormone therapy or targeted therapy, depending on the type of breast cancer you have. Chemotherapy for advanced breast cancer is generally palliative in nature, meaning its main goal is to improve quality and length of life rather than to cure the disease. In a very few cases, though, chemotherapy can lead to total remission of the cancer.
Each woman's experience with chemotherapy's side effects is different, partly due to differences among drugs and dosages and partly due to the body's unique reaction to these medicines. Most side effects are temporary and subside once treatment is finished. But in some cases, chemotherapy can have long-term or even permanent effects.
Short-term side effects
In the process of killing cancer cells, chemotherapy drugs can also damage other rapidly dividing healthy cells, such as those in the hair follicles, bone marrow and digestive tract. The results may include:
- Hair loss
- Loss of appetite
- Mouth sores
- Fatigue (due to fewer red blood cells)
- Increased risk of bruising or bleeding (due to fewer blood platelet cells that help blood clot)
- Increased vulnerability to infections (due to fewer white blood cells that help fight infection)
Various drugs may be used to help reduce nausea and vomiting caused by chemotherapy. In addition, doctors can sometimes adjust the dose or schedule of the chemotherapy drugs to minimize side effects. If chemotherapy has damaged your infection-fighting blood cells, a doctor may adjust your doses of chemotherapy or may add medications that help your bone marrow to recover more quickly. Most side effects don't last long.
Long-term side effects
Certain chemotherapy drugs for breast cancer can cause long-term side effects, including:
Infertility. One side effect that may not go away is infertility, which sometimes results from chemotherapy. Some anti-cancer drugs damage ovaries so that they fail to produce hormones. This may cause typical symptoms of menopause, such as hot flashes and vaginal dryness. Menstrual periods may become irregular or stop (amenorrhea). If ovulation ceases, pregnancy becomes impossible.
If you continue to menstruate, you may still be able to get pregnant even during treatment. But because the effects of chemotherapy are dangerous to the fetus, talk with your doctor about birth control options before treatment begins.
- Nerve damage (neuropathy). Several chemotherapy drugs can affect nerve endings in your hands and feet, leading to feelings of numbness, pain, burning or tingling, sensitivity to cold or heat, or weakness in your extremities. These side effects often go away after treatment is finished, but in some cases, they may be long lasting.
- Osteoporosis. Women who experience menopause early because of chemotherapy may have a higher risk of the bone-thinning condition osteoporosis. It's generally recommended that these women have periodic bone density tests and may consider treatments to prevent bone loss.
- Cognitive function. "Chemo brain," "chemo fog" and "chemo memory" are terms used to describe little-understood short-term memory and concentration problems that occur after chemotherapy. In most cases, these problems go away within a few years.
- Heart damage. When used for a long time and in high doses, some drugs — such as doxorubicin (Adriamycin), epirubicin (Ellence) and others — can cause permanent heart damage.
- Leukemia. Rarely, chemotherapy for breast cancer triggers a secondary cancer, such as cancer of the blood cells (leukemia).
Other side effects
Feelings of fear, sadness and isolation can compound the physical side effects of chemotherapy, both during and after treatment. In fact, some women are unexpectedly sad at the conclusion of treatment. During chemotherapy, women with breast cancer have regular contact with and support from oncologists and nurses. Everyone involved is working toward the same goal — completion of treatment with the best possible outcome — so there's a shared sense of purpose. When it's over, some women feel as if they've been left alone, with no one to help them return to normal life or deal with fears of breast cancer recurrence. It may help to talk with someone who has been in the same situation. Connect with others via a cancer-survivor hot line, support group or online community.
How you prepare
You and your doctor may go through several steps in preparation for chemotherapy.
Assess the potential benefit of chemotherapy
Your doctor considers a number of factors to determine whether and what kind of chemotherapy would be of benefit to you. The higher your risk of recurrence or metastasis, the more likely chemotherapy will be of benefit. In some cases, characteristics of the breast cancer itself may suggest other more beneficial treatments. Discuss your own treatment goals and preferences with your doctor. Factors commonly considered include:
- Tumor size and grade. The more advanced the tumor, the more likely chemotherapy may be useful in destroying any stray cancer cells.
- Lymph node status. If breast cancer cells were found in your lymph nodes during or before surgery, this is an indication of a higher risk of metastasis and thus an indication for chemotherapy.
- Age. Some studies suggest that breast cancer which occurs at a young age is more aggressive than is breast cancer that develops later in life. Thus, doctors may opt for adjuvant chemotherapy when treating younger women to decrease the chances of the cancer spreading to other areas of the body.
- Previous treatments. Whether you've had chemotherapy before may affect your current treatment regimen.
- Chronic health conditions. Certain health problems, such as heart disease or diabetes, may affect your choice of chemotherapy drugs.
- Hormonal status. If your breast cancer is sensitive to the hormones estrogen (ER) and progesterone (PR), hormone therapy — with drugs such as tamoxifen, fulvestrant (Faslodex) or aromatase inhibitors (Arimidex, Femara, Aromasin) — may be a better option for post-surgical adjuvant therapy or they may be considered in addition to chemotherapy.
- HER2 status. If your breast cancer produces (expresses) too much of a growth-promoting protein known as human growth factor receptor 2 (HER2), your doctor may recommend drugs that specifically target this protein — trastuzumab (Herceptin), lapatinib (Tykerb) — in addition to chemotherapy.
- Genetic profile. For certain types of breast cancer, some doctors may use genetic tests (Oncotype DX, MammaPrint) of tissue from the tumor to learn genetic patterns that may help predict the risk of recurrence. These tests are still considered experimental by some.
Take steps to improve your overall health
Because chemotherapy at any time can affect fast-growing healthy cells, such as your white blood cells, platelets and red blood cells, it helps to be as healthy as possible before you begin treatment, to minimize its side effects. Your doctor may recommend that you take the following steps to optimize your overall health:
- Get plenty of rest.
- Eat a balanced diet rich in fruits, vegetables and whole grains.
- Minimize stress.
- Avoid infections, such as the common cold and the flu. Talk to your doctor about recommended immunizations, including annual flu vaccines.
- See your dentist for any signs of infection in your teeth or gums.
- Undergo blood tests to check your liver function and tests to check your heart. If there are any problems, your doctor may delay your treatment or select a chemotherapy drug and dosage that are safer for you.
Plan ahead for side effects
Ask your doctor what side effects you can expect during and after chemotherapy, and make appropriate arrangements. For instance, if your chemotherapy treatment will cause infertility, you may wish to store sperm or fertilized eggs for future use. If your chemotherapy will cause hair loss, consider planning for a wig or head covering.
Make arrangements for help at home and at work
Most chemotherapy treatments are given in an outpatient clinic, which means most people are able to continue working and doing their usual activities during chemotherapy. Your doctor can tell you how much the chemotherapy will affect your usual activities, but it's difficult to predict just how you'll feel. Plan ahead by asking for time off work or help around the house for the first few days after treatment. If you'll be in the hospital during chemotherapy treatment, make arrangements to take time off work, and find a friend or family member to take care of your children, pets or home.
Tell your doctor about any drugs or supplements you're taking
Be sure your doctor knows about any medications or supplements you're taking, including any herbal supplements, vitamins or over-the-counter drugs. These may have an effect on the way the chemotherapy drugs work. Your doctor may suggest alternative medications or not taking the medications or supplements for a period before or after a chemo session.
The day of treatment
Your doctor or nurse will let you know what you can and can't eat or drink on the day of your chemo session. It may help to take a family member or friend with you to the treatment session, for support and companionship.
What you can expect
Timing and frequency of chemotherapy sessions
Chemotherapy for breast cancer is usually given over three to six months, with three-week cycles. For instance, if you had chemotherapy today, you might receive the next treatment in three weeks, allowing you a period of recovery between treatments. If you have advanced breast cancer, treatment may be continued beyond six months.
In some cases, you and your doctor may choose cycles of chemotherapy that are closer together, such as every two weeks (dose-dense chemotherapy) rather than three. This may decrease the risk of recurrence, but it can also lead to more intense side effects.
Adjuvant chemotherapy is usually started two to six weeks after surgery.
Common drug combinations
There's an array of chemotherapy drugs available. Because each woman is different, doctors tailor certain types and doses of medications (regimens) — often a combination of chemotherapy drugs — to a woman's type of breast cancer and her personal medical history. In general, chemotherapy regimens fall into the following categories:
- Anthracycline-based regimens. Anthracyclines are anti-tumor antibiotics that work in all phases of a cell life cycle. They're widely used for a variety of cancers, including breast cancer. Examples of anthracyclines include doxorubicin, epirubicin and idarubicin (Idamycin PFS). These are frequently combined with other drugs, such as cyclophosphamide (Cytoxan) and fluorouracil (5-FU). Anthracyclines are more often associated with hair loss and vomiting, as well as a long-term risk of heart damage when given in high doses. If you have an existing heart condition, your doctor may avoid an anthracycline-based regimen.
- Alkylating agents. Cyclophosphamide is one of the most commonly used of these agents. Cyclophosphamide works to stop cancer cells from reproducing. It's typically used in combination with an anthracycline, methotrexate (Trexall) or 5-FU. Methotrexate and 5-FU are antimetabolites that interfere with cancer cell growth by substituting key protein building blocks. High doses of cyclophosphamide carry a risk of leukemia developing many years later and of possible damage to the bladder.
- Taxanes. Taxanes (Taxol, Taxotere) inhibit mitosis, the phase in a cell cycle where the cell splits in two. By doing this, they can inhibit tumor growth. Taxanes are some of the most recently developed chemotherapy drugs. They're often added to an anthracycline-based regimen to increase the overall survival benefit. Taxanes tend to cause fewer side effects such as nausea and vomiting, but they are associated with nerve damage at high doses.
Where chemotherapy is given
Chemotherapy sessions are generally given on an outpatient basis. Most breast cancer chemo sessions take place at one of these places:
- A doctor's office
- An outpatient unit in a hospital or clinic
How chemotherapy is given
Chemotherapy drugs can be given in a variety of ways, including pills you take at home. But most often they're given with an injection into a vein (intravenously, or IV). This can be done through:
- An IV needle and tube (catheter) in your hand or wrist.
- A catheter port implanted in your chest prior to beginning chemotherapy. This port stays in place for the duration of your chemotherapy treatment and eliminates the need to find a suitable vein at each treatment session.
A typical chemotherapy session
Not all chemotherapy sessions are alike, but a typical session might follow this order:
- You meet with the health care provider who's administering your chemotherapy.
- You undergo a brief physical exam to check temperature, pulse and blood pressure.
- You have the IV catheter inserted.
- You have a blood sample drawn for a blood count and other blood tests.
- You meet with your doctor to review your blood test results and assess your overall health.
- Your doctor orders the chemotherapy.
- You receive medications to prevent side effects such as nausea, anxiety or inflammation.
- You receive the chemotherapy drugs. This may take up to several hours (in some cases, such as if you're hospitalized, the drugs may be given over several days by continuous infusion).
After a chemotherapy session
Following a chemotherapy session, you may:
- Have your catheter removed.
- Have your vital signs checked.
- Review side effects with your health care provider.
- Receive prescriptions for medications you can take at home to help with side effects.
- Be advised to drink a lot of fluids.
- Receive instructions on proper handling of bodily fluids, such as urine, stool, vomit, semen and vaginal secretions, as these may contain some of the chemotherapy drugs for the next 48 hours. This may simply involve flushing the toilet twice after use.
Some women feel fine after a chemotherapy session and can return to their regular schedules, but others may feel side effects more quickly. You may want to arrange for someone to drive you home afterward, at least for the first few sessions, until you see how you feel afterward.
During the course of chemotherapy
After a few sessions, you may be able to predict more accurately when you'll feel fine and when you may need to cut back on activities. Marking your calendar or keeping a journal may help you track your general response to chemotherapy sessions and help you plan events accordingly.
Following your treatment plan closely is the best way to get the most benefit from your chemotherapy. If side effects become too bothersome, discuss them with your doctor. It's likely he or she will be able to adjust the dose or type of chemotherapy medication you're receiving or prescribe other medications to help minimize side effects.
After you complete your chemotherapy treatment, your doctor will schedule follow-up visits — usually every four to six months at first and then less frequently the longer you remain cancer-free. This will be done to monitor you for long-term side effects and to check for recurrence of the breast cancer. Tests and procedures during follow-up care include:
- A careful review of your medical history, especially any signs or symptoms you experience after chemotherapy
- Physical exam, including breast exam
- Yearly mammogram
- Bone density testing
Tests such as tumor marker tests, liver function tests, bone scans and chest X-rays generally aren't recommended unless there is a specific need. Additional imaging tests are typically needed only when a recurrence is suspected.
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