Whether you or a loved one was recently diagnosed with triple-negative breast cancer (TNBC) or has been treating it for a while, you may want to learn more about treatment options. It’s true that there are fewer therapies available for TNBC compared with other types of breast cancer. Chemotherapy is the main treatment for TNBC, and it may also be combined with immunotherapy.

In this article, we’ll cover five important things to know about chemotherapy for TNBC, including when it’s used, what drugs are commonly prescribed, and how it’s combined with other therapies. If you have questions about your treatment options for TNBC, talk to your doctor or oncologist (cancer specialist).

What Is Chemotherapy?

Chemotherapy is an important part of breast cancer treatment that uses cytotoxic (cell-killing) chemicals. These drugs work by interfering with how cells replicate their DNA, grow, and divide. Blocking this process causes rapidly growing cancer cells to die, which shrinks tumors to treat TNBC.

Chemotherapies are usually given as IV infusions in hospitals and infusion centers. Some chemo drugs are taken by mouth as well. Chemotherapy is considered a systemic treatment because it travels throughout your bloodstream and body, whereas localized treatments like surgery and radiation affect just one area.

Overall, chemotherapy treatments for TNBC and other types of breast cancer are very similar. To help you better understand your treatment options, we explain five key aspects.

1. Chemotherapy Is the Main Treatment for Triple-Negative Breast Cancer

Breast cancer is divided into groups depending on which hormones the cells use to grow. Most breast cancers rely on estrogen and/or progesterone to grow and divide rapidly. Other breast cancer cells have too many copies of the HER2 gene. Certain breast cancer treatments target estrogen receptors, progesterone receptors, and HER2 to stop cancer cells from growing uncontrollably.

If you’re diagnosed with TNBC, your breast cancer cells don’t have any estrogen or progesterone receptors, and they don’t produce much HER2 protein. This means that some of the most common breast cancer treatments — like hormone therapy — don’t work for TNBC. Instead, doctors use chemotherapy as the main treatment to shrink breast cancer tumors.

TNBC is more sensitive to chemotherapy than hormone receptor (HR)-positive breast cancers. Most TNBC treatment plans involve chemotherapy combined with other treatments like surgery, radiation, and targeted therapies. The type of treatments you receive and the order in which you receive them will depend on how your cancer is staged.

2. Chemotherapy May Come Before or After Breast Cancer Surgery

People with stages 1, 2, or 3 TNBC may be treated with a combination of surgery, chemotherapy, and radiation therapy. Chemotherapy can be given before or after surgery, depending on how large the tumor is.

Chemotherapy After Surgery

If your tumor is small enough to be removed with surgery, your oncologist may recommend surgery first. A lumpectomy or breast-conserving surgery removes the tumor and leaves the rest of the breast tissue, while a mastectomy removes the entire breast. The decision about which surgery to choose is ultimately up to you, but your doctor can help you weigh the pros and cons of each procedure.

After surgery, you may receive chemotherapy to kill any cancer cells left behind, even those that can’t be seen with the naked eye or on imaging tests. This is known as adjuvant chemotherapy, and it helps prevent remaining cancer cells from forming new tumors. Adjuvant chemotherapy also reduces the chances of your TNBC returning.

Chemotherapy Before Surgery

Neoadjuvant chemotherapy is given before surgery to shrink tumors before your doctor removes them. Other tumors spread into many of the nearby lymph nodes and complicate surgery. Overall, studies show that neoadjuvant chemotherapy can improve your prognosis (outlook) with TNBC.

Around 20 percent of TNBC cases also have a specific protein called programmed cell death ligand 1 (PD-L1). Doctors can prescribe pembrolizumab (Keytruda), an immunotherapy that targets PD-L1, along with chemotherapy for neoadjuvant treatment. After surgery, more pembrolizumab can be given to lower the chances of TNBC returning.

The American Cancer Society also notes that neoadjuvant chemotherapy can give people extra time to decide on breast reconstruction surgery or get genetic testing done to determine their treatment plan.

Read about why TNBC tends to be more aggressive and grow faster than other types of breast cancer.

3. People With Stage 4 Triple-Negative Breast Cancer Usually Get Chemotherapy First

Stage 4 cancer refers to cancer that has spread from a tumor to other parts of the body. Since the cancer is in more than one spot, surgery and radiation typically aren’t used. Doctors treat people who have stage 4 TNBC with chemotherapy first to target as many body parts with cancer as possible.

Chemotherapy plus the immunotherapy pembrolizumab is the first treatment option for people whose cancer cells have PD-L1. Immunotherapies use the immune system to seek and destroy cancer. Studies show that this drug combination is more effective than chemotherapy or immunotherapy alone for treating TNBC. One clinical trial known as Keynote-355 found that people who received chemotherapy and pembrolizumab lived longer than those who received only chemotherapy.

In addition to chemotherapy, your oncologist may prescribe poly (ADP-ribose) polymerase (PARP) inhibitors like talazoparib (Talzenna) and olaparib (Lynparza).

If you have advanced or metastatic TNBC and other treatments haven’t worked, your doctor may recommend another type of immunotherapy known as an antibody-drug conjugate. Antibody-drug conjugates combine a monoclonal antibody, or synthesized immune protein, to deliver a cancer-killing drug directly to breast cancer cells.

Sacituzumab govitecan-hziy (Trodelvy) is an antibody-conjugate drug that targets and binds to a protein called trophoblast cell-surface antigen 2 (TROP2) on cancer cells. It then releases a drug that causes the cell to die.

Read more about immunotherapy for TNBC.

4. Specific Chemotherapy Drugs Are Used To Treat Triple-Negative Breast Cancer

The types of chemotherapy drugs your doctor uses depend on the stage of TNBC. Examples of chemotherapy drugs used for TNBC include:

• Taxanes — Docetaxel (Taxotere) and paclitaxel protein-bound (Abraxane)
• Platinum chemotherapies — Carboplatin (Paraplatin) and cisplatin (Platinol)
• Alkylating agents — Cyclophosphamide (Cytoxan)
• Anthracyclines — Doxorubicin and daunorubicin (Cerubidine)
• Antimetabolites — Gemcitabine (Gemzar), capecitabine (Xeloda), and 5-fluorouracil (5-FU)
• Microtubule inhibitors — Eribulin (Halaven)

The National Comprehensive Cancer Network provides treatment recommendations based on TNBC stage and surgery. The exact combination of chemotherapies and other drugs that your doctor uses can vary. Some people receive dose-dense chemotherapies, which use higher doses with shorter amounts of time between treatment rounds.

If you received chemotherapy before surgery, your doctor may recommend following up with the oral chemotherapy drug capecitabine for 18 to 24 weeks. Studies show that this treatment can improve your prognosis with TNBC.

5. Chemotherapy for Triple-Negative Breast Cancer Causes Side Effects

Chemotherapy affects the entire body. These systemic drugs target rapidly dividing cells — not just cancer cells. Although chemotherapy does an excellent job of killing cancer cells, it can harm your body’s healthy cells as well. The side effects you may experience while taking chemotherapy for TNBC can change depending on the drugs you receive, the dose, and how long you’re treated.

Common chemotherapy side effects you may experience include:

• Hair loss
• Fatigue
• Nausea, vomiting, and loss of appetite
• Weight loss
• Mouth sores
• Diarrhea

Chemotherapy can also trigger early menopause or cause infertility for some people. If you’re concerned about the risk of fertility issues or changes to your menstrual cycle, be sure to talk to your doctor.

Taxanes and platinum chemotherapies used for TNBC can lead to neuropathy or nerve damage. You may notice numbness, tingling sensations, or pain in your hands, feet, arms, and legs. Your symptoms will likely go away once you stop chemotherapy treatment.

Talk With Others Who Understand

MyBCTeam is the social network for people with breast cancer and their loved ones. On MyBCTeam, more than 67,000 members come together to ask questions, give advice, and share their tips with others who understand life with breast cancer.

Have you been treated with chemotherapy while living with triple-negative breast cancer? Share your experiences in the comments below, or start a conversation by posting on your Activities page.