Chemotherapy for Breast Cancer: What to Know to Feel Prepared

Chemotherapy is a common and effective treatment for breast cancer, but it can come with side effects. Here’s how it works, when it’s used, and what to expect during and after treatment.

Chemotherapy is a common and effective treatment for breast cancer. It works by using powerful drugs to destroy or disrupt the growth of fast-growing cells, including cancer cells. It’s typically used in combination with other treatments, such as surgery, radiation, or targeted therapies.

For many patients, undergoing chemotherapy for breast cancer can feel scary and daunting. While this lifesaving treatment can help shrink larger tumors, kill cancer cells that may have spread, and lower a person’s risk of cancer coming back (recurrence), it often comes with difficult side effects and the risk of rare but lasting health problems. It’s important to work with your care team to weigh chemotherapy’s potential benefits against its possible long-term impacts.

If your doctor has recommended chemotherapy as part of your treatment plan, understanding how it works and what to expect can help feel better prepared for what lies ahead. Here’s what to know about chemotherapy for breast cancer, including how it works, the most common drugs, and potential side effects.

What is chemotherapy for breast cancer?

Chemotherapy for breast cancer is a type of treatment that involves administering one or more drugs into the body to kill cancer cells. The drugs enter the bloodstream and are circulated throughout the body to destroy cancer cells. They can be injected into a vein via an infusion or taken orally as a pill.

Chemotherapy for breast cancer is often given in combination with other therapies. Unlike treatments that target a specific area of the body such as surgery or radiation, chemotherapy is a systemic therapy, meaning it affects the entire body. This makes it especially useful for treating cancer cells that have spread to other parts of the body, even if they’re too small to detect.

But it also means that the drugs can damage fast-growing healthy cells in the body, including those in bone marrow, hair follicles, and the digestive tract. Doctors typically give chemotherapy for breast cancer in cycles, followed by periods of rest, to give the patient’s body time to recover and replenish healthy cells.

Chemotherapy for breast cancer has advanced significantly since the 1960s and 70s when its use became more widespread. Doctors can now choose from a variety of chemo drugs including those specific for different types of breast cancer or that speed up treatment time, and they can reduce the risk of severe side effects common in early chemotherapy treatments. Doctors also have a better understanding of how to structure chemo schedules, deliver appropriate dosages, and use it in combination with other treatments to improve outcomes. Still, they continue to refine its use and seek different combinations and dosages of chemotherapy drugs to promote  better results.

How does chemotherapy work?

Chemotherapy works by targeting rapidly growing cells and disrupting the process of cell division. Since cancer cells divide rapidly, chemotherapy has a greater effect on them compared to normal cells; they cause cancer cells to either die or lose the ability to reproduce. This helps shrink tumors, slow or stop the growth of cancer, and reduce the risk of recurrence.

Different chemotherapy drugs for breast cancer attack cancer cells in different ways. Some of the main types include:

• Alkylating agents that damage cell DNA to stop cancer cells from dividing
• Antimetabolites that mimic molecules that cancer cells need to replicate DNA, a process that’s necessary for cells to divide and grow
• Topoisomerase inhibitors that prevent a certain enzyme (topoisomerase) from helping DNA replicate
• Mitotic inhibitors that prevent cancer cells from completing mitosis, the process a cell uses to divide and reproduce
• Antitumor antibiotics that block the DNA inside cancer cells from creating copies of itself

Chemotherapy for breast cancer tends to be most effective when it includes the use of more than one chemotherapy drug at a time. Your doctor may recommend a combination of two or three drugs at once, depending on the type and stage of the cancer, your overall health, your medical history, and your preferences and goals.

When is chemotherapy used in breast cancer treatment?

The use of chemotherapy in breast cancer can occur at different points in the treatment plan, depending on the stage of the disease and individual health factors.

Neoadjuvant chemotherapy for breast cancer is given before surgery to try to reduce the size of the tumor. If successful, this can make the surgery to remove the tumor less extensive, potentially allowing doctors to switch the procedure from a mastectomy to a lumpectomy. It also gives doctors an opportunity to see how the cancer responds to specific types of chemotherapy drugs and decide whether other drugs may be more effective after surgery. In some early-stage cases, recent research suggests that patients who respond especially well to neoadjuvant chemotherapy and radiation treatment may even be able to avoid surgery altogether.

Chemotherapy can also be given after surgery. This is called adjuvant chemotherapy for breast cancer, and it’s used to try to kill cancer cells that may remain in the body after the procedure. These cells don’t show up on imaging tests but can still form new tumors if they grow. Chemotherapy can destroy these cells and help reduce a woman’s risk of breast cancer coming back (recurrence). Certain tests, such as Oncotype DX^®  or MammaPrint, can help oncologists determine whether adjuvant chemotherapy can be beneficial for patients with early-stage hormone receptor-positive breast cancer.

Oncologists may also use chemotherapy when cancer has spread beyond the breast and into other organs, like the lungs or liver. It may control the spread of cancer, ease certain symptoms, and help you live longer.

What are the common chemotherapy drugs for breast cancer?

Doctors can use many different breast cancer chemotherapy drugs, often in combinations of two or three at a time. Some of the most common ones include:

• Doxorubicin, epirubicin, and other anthracyclines
• Taxanes, such as docetaxel and paclitaxel
• Capecitabine or 5-fluorouracil
• Cyclophosphamide
• Carboplatin

Other chemotherapy drugs may be used when breast cancer has spread to other parts of the body (metastatic). While combinations of chemo drugs may be used to treat metastatic breast cancer, some cases of advanced breast cancer are often treated with just one type at a time. Options may include:

• Taxanes
• Anthracyclines
• Ixabepilone
• Eribulin
• Carboplatin
• Vinorelbine
• Capecitabine
• Gemcitabine

Antibody-drug conjugates (ADCs) may also be used for patients with metastatic breast cancer. ADCs—like trastuzumab deruxtecan/Enhertu^® and sacituzumab govitecan/Trodelvy^®—are an exciting form of targeted therapy that combine a chemotherapy drug with an antibody to deliver the chemotherapy drug precisely to a cancer cell. Unlike systemic chemotherapy, ADCs are more precise and have less impact on normal cells. Researchers are investigating ADCs’ use for early-stage breast cancers now.

How is chemotherapy given for breast cancer?

Chemotherapy for breast cancer can be given in a few different ways. The most common way is directly into the vein. This can be done as either an injection, which takes a few minutes, or an infusion, which can last anywhere from 30 minutes to several hours. You will typically need to go to an infusion center or hospital to receive chemotherapy.

In many cases, doctors will recommend placing a central venous catheter (CVC) to make chemotherapy treatments easier and more comfortable. These are like slightly larger, sturdier versions of an IV.

While there are several different types of CVCs, most breast cancer patients who receive chemo will either get a central line placed on the opposite side of the body to the breast cancer or on the side with fewer lymph nodes affected by cancer. Peripherally inserted central catheters (PICCs) are another common way to administer chemotherapy for breast cancer. These are inserted into a vein in the arm.

Another potential option for some patients is oral chemotherapy for breast cancer. These medications come in pills that can be taken at home. It can be more convenient than getting an injection or infusion, but it still comes with the risk of side effects.

Oncologists typically give chemotherapy in cycles. In between, patients get a rest period to help recover and allow the body to replenish healthy cells. Chemo cycles typically last two or three weeks, but the exact schedule and duration depends on which drugs are given. Some chemotherapy drugs for breast cancer are only administered on day one of the cycle, while others must be taken once every week or two for several weeks.

Breast cancer patients typically need neoadjuvant (pre-surgery) or adjuvant (post-surgery) chemotherapy for a total of three to six months. If you’re receiving chemotherapy for metastatic breast cancer, the length of treatment depends on how well it’s working and how intense the side effects are.

What are the most common side effects of chemotherapy for breast cancer?

Chemotherapy drugs for breast cancer can affect normal cells and cause a range of side effects. While these effects are usually temporary, they’re very common and can impact how you feel during and shortly after treatment.

Some of the most common side effects of chemotherapy for breast cancer include:

• Hair loss
• Brittle nails
• Dry or itchy skin
• Fatigue
• Gastrointestinal issues, such as diarrhea or constipation
• Loss of appetite
• Weight loss
• Nausea
• Vomiting
• Mouth sores
• Premature menopause
• Hot flashes (from premature menopause)
• Vaginal dryness (from premature menopause)
• Easy bruising
• Increased chance of infections
• Menstrual changes

Everyone responds to treatment differently. While some may feel fine after receiving chemotherapy drugs, most deal with some side effects. In fact, 84 percent of breast cancer patients report experiencing at least one side effect during treatment, according to a 2017 study.

Your doctor may prescribe medications to reduce certain side effects, such as nausea and vomiting. Your healthcare team may also be able to recommend strategies to help cope with fatigue, appetite changes, and other common side effects of chemotherapy for breast cancer.

One side effect that can be particularly uncomfortable is hand-foot syndrome, which sometimes occurs with certain chemotherapy drugs such as liposomal doxorubicin and capecitabine. It causes redness, numbness, swelling, pain, blistering, or peeling on the palms of the hands and soles of the feet. There’s no treatment for this side effect but stopping the drug or lowering the dosage can help symptoms resolve, so it’s important to tell your doctor if you notice any changes to your hands and feet.

Most side effects go away once chemotherapy is complete. However, you may experience some lingering side effects even after treatment ends. Some women who’ve received chemotherapy for breast cancer continue to feel fatigue for a few months or even several years after. Others report feeling less healthy overall than they did before chemo. They may have persistent body aches and pains or slightly less physical functioning.

“Chemo brain” can be common for several years after receiving chemotherapy for breast cancer, as well. It’s also known as cancer-related cognitive impairment because other breast cancer treatments can cause it, too. This condition can feel like mental fog and may include memory loss, difficulty concentrating, and slower thinking. Between 60 percent and 75 percent of cancer patients experience chemo brain, according to a 2025 guide in JCO Oncology Practice.

In rare cases, chemotherapy can lead to more serious complications. Some drugs can cause permanent heart damage, especially when used in high doses or for long periods of time. Damage to the nerves in the legs, feet, arms, and hands can also happen after taking certain chemotherapy drugs. This can cause neuropathy, which can include symptoms like pain, tingling, burning sensations, numbness, increased sensitivity to heat or cold, and weakness. It can be long lasting or permanent, but you can take medications to manage these symptoms.

Chemotherapy for breast cancer can also cause changes to menstruation and fertility. Your periods may stop when you’re receiving treatment and there’s a chance you may experience premature menopause. Because chemotherapy can damage the ovaries and reduce how many viable eggs you have, it may also affect your ability to get pregnant in the future. If you’re considering having children after breast cancer treatment, it’s important to talk to your doctor. They may recommend adding certain medications, like luteinizing hormone-releasing hormone (LHRH) analog injections, to your treatment plan to help preserve your fertility.

Certain chemotherapy drugs can increase a person’s risk of leukemia. This is extremely rare. A 2015 study, which analyzed data on more than 20,000 patients with breast cancer from 1998 to 2007, found that 50 participants developed leukemia within 10 years of receiving chemotherapy as part of their treatment. For the most part, the benefits of chemotherapy for breast cancer far outweigh the small risk of leukemia, along with the other short- and long-term side effects that may occur from the treatment.

BCRF’s research on chemotherapy for breast cancer

While chemotherapy has been used to treat breast cancer for decades, BCRF investigators and others are still studying and refining several aspects of its use, from treatment resistance to side effects.

Indeed, BCRF investigators have been behind every major breakthrough in breast cancer research, including practice-changing trials such as TAILORx and RxPONDER. These trials showed that some women could safely forgo chemotherapy and only receive hormone therapy.

BCRF investigators are specifically working to:

• Optimize or develop new chemotherapy partners, such immune checkpoint inhibitors, to improve outcomes for patients
• Devise ways to overcome chemotherapy resistance, particularly in triple-negative breast cancers for which chemotherapy is still the standard of care
• Identify biomarkers of chemotherapy response and develop strategies that predict who will respond to chemotherapy so that some patients can avoid it
• Develop methods to manage side effects to make it easier for patients to finish chemotherapy
• Optimize how chemotherapy drugs are delivered such as through antibody-drug conjugates and by personalziing dosing and schedules
• Develop exercise and nutrition interventions that can boost chemotherapy’s efficacy
• Minimize the accelerated aging effects of chemotherapy

Chemotherapy is an important breast cancer treatment. Through research, we’ll better be able to identify who needs it, minimize side effects, and improve outcomes.

Selected References

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Kuerer, H. M., Valero, V., Smith, B. D., Krishnamurthy, S., Diego, E. J., Johnson, H. M., Lin, H., Shen, Y., Lucci, A., Shaitelman, S. F., Mitchell, M. P., Boughey, J. C., White, R. L., Hunt, K. K., Yang, W. T., Rauch, G. M., Moseley, T. W., Leung, J. W., Huang, M., . . . Nguyen, T. M. (2025). Selective elimination of breast surgery for invasive breast cancer. JAMA Oncology. https://doi.org/10.1001/jamaoncol.2025.0207

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