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Chemotherapy for Breast Cancer
Chemotherapy (chemo) is sometimes used as part of treatment for breast cancer.
Chemo is the use of medicines to treat cancer. Chemo medicines may be put into a vein (IV) or taken by mouth. They travel through your bloodstream to reach cancer cells in most parts of your body. If breast cancer spreads to the spinal fluid that surrounds and cushions the brain and spinal cord, chemo is sometimes put directly into this area. This is called intrathecal chemotherapy.
When is chemo used for breast cancer?
Not everyone with breast cancer needs chemo, but it might be used in several situations.
Before surgery (neoadjuvant chemotherapy)
Neoadjuvant chemotherapy is chemotherapy given before surgery. The goal is to shrink the tumor so it can be removed with less extensive surgery. It is most often used when:
- The tumor is too large to operate on right away.
- Many lymph nodes are involved with cancer.
- The cancer is inflammatory breast cancer.
Neoadjuvant chemo can shrink a tumor before surgery, but it also has other benefits.
- Doctors can see if the treatment is working. Because the tumor is still in your body during chemo, doctors can watch how it responds. This information can guide treatment decisions before and after surgery.
- It may help you live longer. For people with triple-negative or HER2-positive breast cancer, having the cancer completely disappear before surgery has been linked to better survival.
- It kills hidden cancer cells. Chemo travels through your bloodstream. It can destroy cancer cells that are too small to see on scans, even ones that might have spread to other parts of your body.
- It gives you extra time to prepare. Some people use this time before surgery to have genetic testing or plan for reconstruction.
When cancer cells are still found during surgery, this is called residual disease. If you have residual disease, your doctor may recommend more chemo after surgery to lower the chance of the cancer coming back.
Neoadjuvant chemo is not the right choice for everyone. Your care team will help you decide if it makes sense for you.
After surgery (adjuvant chemotherapy)
Adjuvant chemotherapy is chemo given after surgery. The goal is to kill any cancer cells that might have been left behind or spread to other parts of your body. These cells are too tiny to see on scans or with the naked eye, but they can grow into new tumors if they are left untreated.
Research shows chemo is equally effective before or after surgery.
Adjuvant chemo can help by:
- Lowering the risk of the cancer coming back. Even after a successful surgery, chemo acts as a safety net against cells that could not be found or removed.
- Reaching cancer anywhere in your body. Chemo travels through your bloodstream, so it can target cancer cells that may have spread beyond the breast.
Do I need chemo? Not everyone with early-stage breast cancer will benefit from chemo. Certain tests look at the genes in your tumor to help predict whether chemo is likely to help you. Your cancer care team can use these test results to make a treatment plan that fits your specific cancer.
Learn more in Breast Cancer Gene Expression Tests.
For metastatic breast cancer
Chemotherapy is often the main treatment when breast cancer has spread to distant parts of the body like the liver or lungs. It can be started right after you are diagnosed or after other treatments have been tried.
- Chemo can reach cancer anywhere in your body. It travels through your bloodstream, so it can go after cancer cells that have spread far from your breast.
- Treatment length is different for everyone. How long you take chemo will depend on how well it's working and how well your body handles it.
Treatment often continues until the cancer starts growing again or until side effects become unacceptable. If this happens, another chemo medicine or a different type of medicine might be tried.
Chemo medicines used for breast cancer
In most cases, chemo has the greatest effect when more than one medicine is used at a time. Combinations of 2 or 3 medicines are often used. Doctors use many different combinations. It’s not clear that any particular combination is the best.
Early breast cancer is usually treated with a combination of chemo medicines. Advanced breast cancer is often treated with just one medicine at a time. However, some combinations are still commonly used for metastatic breast cancer.
For HER2-positive breast cancers, one or more medicines that target HER2 may be used with chemo. You can learn more about these medicines in Targeted Therapy for Breast Cancer.
- Anthracyclines: Doxorubicin (Adriamycin)
- Taxanes: Paclitaxel (Taxol) and docetaxel (Taxotere)
- 5-fluorouracil (5-FU) or capecitabine (Xeloda)
- Cyclophosphamide (Cytoxan)
- Carboplatin (Paraplatin)
Chemo medicines commonly used for advanced breast cancer include:
- Taxanes: Paclitaxel (Taxol), docetaxel (Taxotere), and albumin-bound paclitaxel (Abraxane)
- Ixabepilone (Ixempra)
- Eribulin (Halaven)
- Anthracyclines: Doxorubicin (Adriamycin), liposomal doxorubicin (Doxil), and epirubicin? (Ellence)
- Cisplatin (Platinol)
- Vinorelbine (Navelbine)
- Capecitabine (Xeloda)
- Gemcitabine (Gemzar)
- Cyclophosphamide (Cytoxan)
- Antibody-drug conjugates: Ado-trastuzumab emtansine (Kadcyla), Fam-trastuzumab deruxtecan (T-DXd, Enhertu), Sacituzumab govitecan (Trodelvy), Datopotamab deruxtecan (Datroway)
How is chemo given for breast cancer?
Chemo for breast cancer is usually put into a vein (IV). This is done either as an injection over a few minutes or as an infusion over a longer period of time. It can happen in a doctor’s office, infusion center, or hospital.
A slightly larger and sturdier IV called a central line is often needed to deliver the chemo. This is used to put medicines, blood products, nutrients, or fluids right into your blood. It can also be used to take out blood for testing.
For people who are likely to need radiation to the chest wall, the central line is usually placed on the side opposite the cancer. If you have cancer in both breasts, the central line will most likely be placed on the side that had fewer lymph nodes removed or involved.
Common chemo cycles
Chemo is given in cycles: one medicine or a combination of medicines is given on a set schedule, followed by a rest period to give you time to recover. This period of chemo and rest is considered one cycle.
Chemo cycles are most often 2 or 3 weeks long. The schedule varies depending on the medicines used. For example, with some medicines, chemo is given only on the first day of the cycle. With others, it is given one day a week for a few weeks or every other week. At the end of the cycle, the chemo schedule repeats to start the next cycle.
Length of time
- Adjuvant and neoadjuvant chemo is often given for a total of 3 to 6 months, depending on the medicines used.
- The length of treatment for metastatic breast cancer depends on how well it is working and what side effects you have.
Dose-dense chemotherapy
Doctors have found that giving the cycles of certain chemo medicines closer together can lower the chance that the cancer will come back and improve survival for some women with breast cancer.
For example, a medicine that would normally be given every 3 weeks might be given every 2 weeks. This can be done for both neoadjuvant and adjuvant treatment. It can lead to more problems with low blood cell counts, so it’s not an option for everyone.
One chemo combination sometimes given this way is doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan) every 2 weeks, followed by paclitaxel (Taxol).
Possible side effects
Chemo medicines can cause a variety of side effects. These side effects depend on the type and dose of medicine and how long treatment lasts.
Some of the most common possible side effects include:
- Hair loss
- Nail changes
- Mouth sores
- Loss of appetite or weight changes
- Nausea and vomiting
- Diarrhea
- Extreme tiredness (fatigue)
- Numbness and tingling of hands and/or toes (neuropathy)
- Hot flashes and/or vaginal dryness from menopause caused by chemo
Chemo can also affect the blood-forming cells in your bone marrow. This 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 usually go away after treatment ends, and there are often ways to reduce them. For example, you can take medicines to help prevent or reduce nausea and vomiting.
Some side effects, such as numbness and tingling from nerve damage, may not completely go away. Other side effects, such as heart disease, may start after you finish treatment.
If you had menstrual periods before chemo, they can be affected by treatment. In some cases, your periods may stop permanently. This is called premature menopause.
Some people lose the ability to get pregnant. If you think you might want to have children after treatment, talk to your healthcare team as soon as possible. Do this before you start treatment, if you can. Some people get monthly shots called LHRH analogs during chemo. These may help protect the ability to get pregnant later.
Birth control during chemo is important because getting pregnant during treatment can harm the baby and interfere with your care. Keep these things in mind:
- Hormonal birth control, like the pill, is not safe if your breast cancer is hormone receptor-positive. Talk with your oncologist and gynecologist about your options.
- Once you finish treatment, it’s generally safe to become pregnant.
If you are already pregnant when you are diagnosed, treatment is still possible. Certain chemo medicines can be given safely during the second and third trimesters of pregnancy. See Treating Breast Cancer During Pregnancy for more details.
Some chemo medicines, such as doxorubicin and epirubicin, can cause permanent heart damage. This is known as cardiomyopathy. It is not common, but the risk is higher if:
- The medicine is used for a long time or at high doses.
- You take other heart-damaging medicines at the same time, such as HER2-targeted therapies.
- You have other heart risk factors like high blood pressure, diabetes, or a family history of heart problems.
Most doctors will check how well your heart works before you start these medicines. They will probably test this with an echocardiogram (ECHO) or a MUGA scan. During treatment, they will carefully control your doses and watch for symptoms. They may repeat heart tests along the way.
If your heart function starts to get worse, the medicine will be paused or stopped. In some cases, signs of damage may not appear until months or years after treatment ends.
Some chemo medicines used to treat breast cancer can damage nerves in your hands, arms, feet, and legs. This is called peripheral neuropathy.
Medicines that can cause this include taxanes (docetaxel, paclitaxel, and protein-bound paclitaxel), platinum agents (carboplatin and cisplatin), vinorelbine, eribulin, and ixabepilone.
Symptoms can include:
- Numbness, tingling, or burning
- Pain or sensitivity to cold or heat
- Weakness
These symptoms usually go away over time after treatment ends, but for some people they can last a long time or become permanent. Medicines can help manage these symptoms.
Some chemo medicines used to treat breast cancer can irritate the palms of your hands and soles of your feet. This is called hand-foot syndrome.
Medicines that can cause this include capecitabine (Xeloda) and liposomal doxorubicin (Doxil).
- Early signs include numbness, tingling, and redness.
- As it progresses, your hands and feet may become swollen and painful.
- In severe cases the skin can blister, peel, or develop open sores.
There is no specific treatment, although it may help to get certain creams or steroids before chemo. Symptoms usually improve when the chemo medicine is stopped or the dose is lowered.
Tell your cancer care team as soon as symptoms start. Catching it early makes it easier to adjust your dose or add other medicines before it gets worse.
Many people treated with chemo report problems with memory and concentration. This is often called chemo brain. It can last for a long time, but most people are still able to go about their daily lives.
Interestingly, some women who did not receive chemo have reported the same problems. This suggests other factors might play a role. When chemo brain is linked to treatment, symptoms may last for a few years.
In very rare cases, doxorubicin (Adriamycin) and certain other chemo medicines can cause diseases of the bone marrow, such as myelodysplastic syndromes or even acute myeloid leukemia (AML). AML is a cancer of white blood cells.
If this happens, it is usually within 10 years after treatment.
This is a rare complication. For most people, the benefits of chemo in extending life or helping prevent breast cancer from coming back far outweigh the risk.
Fatigue is another common problem for people who get chemo. This might last anywhere between a few months and a few years. It can often be helped, so it’s important to let your cancer care team know about it. They may recommend exercise, naps, and conserving energy.
If you have sleep problems, these can be treated. Sometimes fatigue can be a sign of depression. This may be helped by counseling, medicines, or both.
Other side effects are also possible. Some of these are more common with certain chemo medicines. Ask your cancer care team about the possible side effects of the medicines you're getting.
More information about chemotherapy
For more general information about how chemotherapy is used to treat cancer, see Chemotherapy.
To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.
- Written by
- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
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Last Revised: July 9, 2026
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