- How is breast cancer treated?
- Surgery for breast cancer
- Radiation therapy for breast cancer
- Chemotherapy for breast cancer
- Hormone therapy for breast cancer
- Targeted therapy for breast cancer
- Bisphosphonates for breast cancer
- Denosumab for breast cancer
- Clinical trials for breast cancer
- Complementary and alternative therapies for breast cancer
- Treatment of non-invasive (stage 0) breast cancer
- Treatment of invasive breast cancer, by stage
- Treatment of breast cancer during pregnancy
- More treatment information for breast cancer
Chemotherapy for breast cancer
Chemotherapy (chemo) is treatment with cancer-killing drugs that may be given intravenously (injected into a vein) or by mouth. The drugs travel through the bloodstream to reach cancer cells in most parts of the body. Chemo is given in cycles, with each period of treatment followed by a recovery period. Treatment usually lasts for several months.
When is chemotherapy used?
There are several situations in which chemo may be recommended.
After surgery (adjuvant chemotherapy): When therapy is given to patients with no evidence of cancer after surgery, it is called adjuvant therapy. Surgery is used to remove all of the cancer that can be seen, but adjuvant therapy is used to kill any cancer cells that may have been left behind but can't be seen. Adjuvant therapy after breast-conserving surgery or mastectomy reduces the risk of breast cancer coming back. Radiation, chemo, and hormone therapy can all be used as adjuvant treatments.
Even in the early stages of the disease, cancer cells may break away from the primary breast tumor and spread through the bloodstream. These cells don't cause symptoms, they don't show up on imaging tests, and they can't be felt during a physical exam. But if they are allowed to grow, they can establish new tumors in other places in the body. The goal of adjuvant chemo is to kill undetected cells that have traveled from the breast.
Before surgery (neoadjuvant chemotherapy): Chemo given before surgery is called neoadjuvant therapy. Often, neoadjuvant therapy uses the same chemo that is used as adjuvant therapy (only it is given before surgery instead of after). In terms of survival, there is no difference between giving chemo before or after surgery. The major benefit of neoadjuvant chemo is that it can shrink large cancers so that they are small enough to be removed with less extensive surgery. The other advantage of neoadjuvant chemo is that doctors can see how the cancer responds to the chemo drugs. If the tumor does not shrink with the first set of drugs, your doctor will know that other chemo drugs are needed.
Some breast cancers are too big to be surgically removed at the time of diagnosis. These cancers are referred to as locally advanced and have to be treated with chemo to shrink them so they can be removed with surgery.
For advanced breast cancer: Chemo can also be used as the main treatment for women whose cancer has spread outside the breast and underarm area, either when it is diagnosed or after initial treatments. The length of treatment depends on whether the cancer shrinks, how much it shrinks, and how a woman tolerates treatment.
How is chemotherapy given?
In most cases (especially adjuvant and neoadjuvant treatment), chemo is most effective when combinations of more than one drug are used. Many combinations are being used, and it's not clear that any single combination is clearly the best. Clinical studies continue to compare today's most effective treatments against something that may be better.
Some of the most commonly used drug combinations are:
- CMF: cyclophosphamide (Cytoxan®), methotrexate, and 5-fluorouracil (fluorouracil, 5-FU)
- CAF (or FAC): cyclophosphamide, doxorubicin (Adriamycin®), and 5-fluorouracil
- AC: doxorubicin (Adriamycin) and cyclophosphamide
- EC: epirubicin (Ellence®) and cyclophosphamide
- TAC: docetaxel (Taxotere®), doxorubicin (Adriamycin), and cyclophosphamide
- AC → T: doxorubicin (Adriamycin) and cyclophosphamide followed by paclitaxel (Taxol®) or docetaxel (Taxotere). Trastuzumab (Herceptin) may be given with the paclitaxel or docetaxel for HER2/neu positive tumors.
- A → CMF: doxorubicin (Adriamycin), followed by CMF
- CEF (FEC): cyclophosphamide, epirubicin, and 5-fluorouracil (this may be followed by docetaxel)
- TC: docetaxel (Taxotere) and cyclophosphamide
- TCH: docetaxel, carboplatin, and trastuzumab (Herceptin) for HER2/neu positive tumors
Other chemo drugs used to treat women with breast cancer include cisplatin, vinorelbine (Navelbine®), capecitabine (Xeloda®), liposomal doxorubicin (Doxil®), gemcitabine (Gemzar®), mitoxantrone, ixabepilone (Ixempra®), albumin-bound paclitaxel (Abraxane®), and eribulin (Halaven®). The targeted therapy drugs trastuzumab and lapatinib (Tykerb®) may be used with these chemo drugs for tumors that are HER2/neu-positive (these drugs are discussed in more detail in the "Targeted therapy for breast cancer" section).
Doctors give chemo in cycles, with each period of treatment followed by a rest period to give the body time to recover from the effects of the drugs. Chemo begins on the first day of each cycle, but the schedule varies depending on the drugs used. For example, with some drugs, the chemo is given only on the first day of the cycle. With others, it is given every day for 14 days, or weekly for 2 weeks. Then, at the end of the cycle, the chemo schedule repeats to start the next cycle. Cycles are most often 2 or 3 weeks long, but it varies according to the specific drug or combination of drugs. Some drugs are given more often. Adjuvant and neoadjuvant chemo is often given for a total time of 3 to 6 months, depending on the drugs that are used. Treatment may be longer for advanced breast cancer and is based on how well it is working and what side effects the patient has.
Dose-dense chemotherapy: Doctors have found that giving the cycles of certain chemo agents closer together can lower the chance that the cancer will come back and improve survival in some women. This usually means giving the same chemo that is normally given every 3 weeks (such as AC → T), but giving it every 2 weeks. A drug (growth factor) to help boost the white blood cell count is given after chemo to make sure the white blood cell count returns to normal in time for the next cycle. This approach can be used for neoadjuvant and adjuvant treatment. It can lead to more side effects and be harder to take, so it isn’t for everyone.
Possible side effects
Chemo drugs work by attacking cells that are dividing quickly, which is why they work against cancer cells. But other cells in the body, like those in the bone marrow, the lining of the mouth and intestines, and the hair follicles, also divide quickly. These cells are also likely to be affected by chemo, which can lead to side effects. Some women have many side effects; others may only have few.
The side effects of chemo depend on the type of drugs, the amount taken, and the length of treatment. Some of the most common possible side effects include:
- Hair loss
- Mouth sores
- Loss of appetite or increased appetite
- Nausea and vomiting
- Low blood cell counts
Chemo can affect the blood forming cells of the bone marrow, which can lead to:
- Increased chance of infections (from low white blood cell counts)
- Easy bruising or bleeding (from low blood platelet counts)
- Fatigue (from low red blood cell counts and other reasons)
These side effects are usually short-term and go away after treatment is finished. It's important to tell your health care team if you have any side effects, as there are often ways to lessen them. For example, drugs can be given to help prevent or reduce nausea and vomiting.
Other side effects are also possible. Some of these are more common with certain chemo drugs. Your cancer care team will tell you about the possible side effects of the specific drugs you are getting.
Menstrual changes: For younger women, changes in menstrual periods are a common side effect of chemo. Premature menopause (not having any more menstrual periods) and infertility (not being able to become pregnant) may occur and may be permanent. Some chemo drugs are more likely to do this than others. The older a woman is when she receives chemotherapy, the more likely it is that she will become infertile or go through menopause as a result. When this happens, there is an increased risk of bone loss and osteoporosis. There are medicines that can treat or help prevent problems with bone loss.
Even if your periods have stopped on chemo, you may still be able to get pregnant. Getting pregnant while receiving chemo could lead to birth defects and interfere with treatment. This is why it’s important that women who are pre-menopausal before treatment and are sexually active discuss using birth control with their doctor. Patients who have finished treatment (like chemo) can safely go on to have children, but it's not safe to get pregnant while on treatment.
If you are pregnant when you get breast cancer, you still can be treated. Certain chemo drugs can be safely given during the last 2 trimesters of pregnancy. This is discussed in detail in the section, “Treatment of breast cancer during pregnancy.”
Neuropathy: Several drugs used to treat breast cancer, including the taxanes (docetaxel and paclitaxel), platinum agents (carboplatin, cisplatin), vinorelbine, erubulin, and ixabepilone, can damage nerves outside of the brain and spinal cord. This can sometimes lead to symptoms (mainly in the hands and feet) like numbness, pain, burning or tingling sensations, sensitivity to cold or heat, or weakness. In most cases this goes away once treatment is stopped, but it might last a long time in some women.
Heart damage: Doxorubicin, epirubicin, and some other drugs may cause permanent heart damage (called cardiomyopathy). The risk of this occurring depends on how much of the drug is given, and is highest if the drug is used for a long time or in high doses. Doctors watch closely for this side effect. Most doctors order a test like a MUGA or an echocardiogram (to check the patient’s heart function) before starting one of these drugs. They also carefully control the doses, watch for symptoms of heart problems, and may repeat the heart test to monitor heart function. If the heart function begins to decline, treatment with these drugs will be stopped. Still, in some patients, heart damage takes a long time to develop. They may not show signs of poor heart function until months or years after treatment stops. Heart damage from these drugs happens more often if the targeted therapy drug trastuzumab is used as well, so doctors are more cautious when these drugs are used together.
Hand-foot syndrome: Certain chemo drugs, such as capecitabine and liposomal doxorubicin, can irritate the palms of the hands and the soles of the feet. This is called hand-foot syndrome. Early symptoms include numbness, tingling, and redness. If it gets worse, the hands and feet become swollen and uncomfortable or even painful. The skin may blister, leading to peeling of the skin or even open sores. There is no specific treatment, but these symptoms gradually get better when the drug is stopped or the dose is decreased. The best way to prevent severe hand-foot syndrome is to tell your doctor when early symptoms come up, so that the drug dose can be changed. This syndrome can also occur when the drug 5-FU is given as an IV infusion over several days (which is not commonly done to treat breast cancer).
Chemo brain: Another possible side effect of chemo is "chemo brain." Many women who are treated for breast cancer report a slight decrease in mental functioning. There may be some problems with concentration and memory, which may last a long time. Although many women have linked this to chemo, it also has been seen in women who did not get chemo as a part of their treatment. Still, most women do function well after treatment. In studies that have found chemo brain to be a side effect of treatment, the symptoms most often go away in a few years. For more information, see our document, Chemo brain.
Increased risk of leukemia: Very rarely, certain chemo drugs can permanently damage the bone marrow, leading to a disease called myelodysplastic syndrome or even acute myeloid leukemia, a life-threatening cancer of white blood cells. When this happens it is usually within 10 years after treatment. In most women, the benefits of chemo in preventing breast cancer from coming back or in extending life are likely to far exceed the risk of this serious but rare complication.
Feeling unwell or tired: Many women do not feel as healthy after receiving chemo as they did before. There is often a residual feeling of body pain or achiness and a mild loss of physical functioning. These may be very subtle changes that are only revealed by closely questioning women who have undergone chemo.
Fatigue is another common (but often overlooked) problem for women who have received chemo. This may last up to several years. It can often be helped, so it is important to let your doctor or nurse know about it. For more information on what you can do about fatigue, see our document, Fatigue in People with Cancer. Exercise, naps, and conserving energy may be recommended. If there are sleep problems, these can be treated. Sometimes there is depression, which may be helped by counseling and/or medicines.
Last Medical Review: 08/23/2012
Last Revised: 02/26/2013