Early Breast Cancer Treatments: Your GoodRx Guide to 5 Common Medications

After a diagnosis of early breast cancer, trying to navigate all of the available treatment options can feel mind-boggling.

Historically, chemotherapy and hormone therapy have been the mainstays of breast cancer treatment. Now, newer medications with alternative methods of fighting breast cancer are available too. Immunotherapy and targeted therapies have emerged as influential treatment options for early breast cancer.

Although it’s nice to have many treatments at your disposal, it can be difficult to understand what it all means and where your situation fits in. Here, we’ll break down the common medications used to treat early breast cancer.

What medications are used in early breast cancer treatment?

Early-stage breast cancer — also known as early breast cancer — refers to breast cancer that hasn’t spread outside of the breast or lymph nodes.

A variety of medications treat early breast cancer. These include chemotherapy, immunotherapy, and hormone therapy. Targeted therapies are options in some cases, too. The best treatments for early breast cancer depend on factors such as the size of the tumor, where it’s located, and the types of receptors (chemical binding sites) that are present on breast cancer cells.

1. Chemotherapy medications for early breast cancer

Chemotherapy for early breast cancer kills rapidly-dividing cancer cells. Depending on your situation, it can be given before or after breast surgery. But if your breast cancer is considered slower-growing, it might not be effective.

Chemotherapy is typically given in cycles, or phases, over 3 to 6 months. It’s often given as an injection into a vein (IV, intravenously), but some can also be taken as an oral pill. These are some common chemotherapies used for early breast cancer management:

• Doxorubicin (Adriamycin)

• Cyclophosphamide (Cytoxan)

• Carboplatin (Paraplatin)

• Epirubicin (Ellence)

• Capecitabine (Xeloda)

• Docetaxel (Taxotere)

• Paclitaxel (Taxol)

• Fluorouracil

• Methotrexate

Oftentimes, two to three chemotherapies are combined to achieve a greater effect. One common chemotherapy regimen that may be used for early breast cancer is cyclophosphamide and docetaxel.

2. Hormone therapy for early breast cancer

When breast cancer cells use estrogen or progesterone as fuel to grow, it’s considered hormone receptor-positive (HR+) breast cancer.

Hormone (endocrine) therapy medications treat early, HR+ breast cancer by blocking or lowering the levels of estrogen and progesterone in the body. Hormone therapy lowers the risk of breast cancer coming back.

Aromatase inhibitors

Aromatase inhibitors (AIs) are common hormone therapies for women with early breast cancer — regardless if they’ve experienced menopause. Top AIs are anastrozole (Arimidex), letrozole (Femara), and exemestane (Aromasin). They’re all available as oral pills that are taken daily for 5 to 10 years at a time.

For women who haven’t gone through menopause, AIs are used in combination with a medication for ovarian suppression, such as leuprolide (Lupron Depot) or goserelin (Zoladex). For women who have experienced menopause, ovarian suppression isn’t necessary.

SERMs

Selective estrogen receptor modulators (SERMs), such as tamoxifen (Soltamox), can be used as hormone therapy for women and men with early breast cancer. SERMs are available as pills taken by mouth daily for 5 to 10 years.

3. Immunotherapy for early breast cancer

Immunotherapy medications work by enhancing your body’s immune system. They aim to help it identify and kill cancer cells more effectively.

Pembrolizumab (Keytruda) is the main immunotherapy used to treat early breast cancer. It works by targeting programmed cell death protein 1 (PD-1) receptors on T cells of the immune system. Blocking PD-1 helps unleash the immune system on breast cancer cells, but it’s not equally effective for all forms of breast cancer.

Pembrolizumab is FDA approved to treat early breast cancer in people whose breast cancer is considered “triple negative.” Triple-negative breast cancer cells don't have any estrogen, progesterone, or HER2 receptors on them; only certain treatments can effectively treat this form of breast cancer.

Pembrolizumab is given in combination with chemotherapy before breast surgery and can be continued by itself after surgery. It's typically given as an IV infusion every 3 to 6 weeks. It helps lower the risk of cancer coming back.

4. Anti-HER2 medications for early breast cancer

Anti-HER2 medications are a type of targeted therapy that work by targeting a protein in the body called human epidermal growth factor receptor 2 (HER2). HER2 may be expressed more on breast cancer cells, and if this is the case, it’s referred to as HER2-positive breast cancer.

Anti-HER2 medications can only treat breast cancer that’s HER2-positive. If your breast cancer is considered HER2-positive, you’ll likely receive one of these medications in combination with chemotherapy.

Trastuzumab

Trastuzumab (Herceptin) works by blocking HER2 proteins on HER2-positive breast cancer cells. This helps slow down breast cancer growth. It’s typically given as an IV infusion every 3 weeks, and it can be given before or after surgery.

Other equally effective versions of trastuzumab are available too. Your cancer specialist may opt to prescribe a trastuzumab biosimilar in place of trastuzumab to save on cost. Or, they may prescribe an under-the-skin equivalent called trastuzumab / hyaluronidase (Herceptin Hylecta).

Pertuzumab

Pertuzumab (Perjeta) also works by blocking HER2 proteins on HER2-positive breast cancer cells. But it works differently than trastuzumab.

Pertuzumab is always given in combination with trastuzumab to treat HER2-positive early breast cancer. They block HER2 in different ways, so they work better together. Pertuzumab is typically injected into the vein every 3 weeks and can be given before or after surgery.

Good to know: A combination product that contains trastuzumab, pertuzumab, and hyaluronidase (Phesgo) is also available. If covered by your insurance, it’s a convenient option that's given as an under-the-skin injection.

Ado-trastuzumab emtansine

Ado-trastuzumab emtansine (Kadcyla) is an antibody-drug conjugate. It combines trastuzumab and a chemotherapy medication into a single treatment. This combination allows for a more targeted delivery of chemotherapy to HER2-positive breast cancer cells.

For HER2-positive, early breast cancer, ado-trastuzumab emtansine can be given to people who have already received cancer treatment before surgery but still have cancer remaining in their breast or lymph nodes at the time of surgery.

Neratinib

Neratinib (Nerlynx) is a tyrosine kinase inhibitor that blocks certain enzymes (proteins) that contribute to cancer growth. It works inside cancer cells to block signaling to HER2 receptors which stops cancer growth. It's given in some circumstances to people with early breast cancer who have already been treated with trastuzumab and still need additional treatment.

Neratinib is a once-daily pill that's taken by mouth for 1 year at a time. It helps prevent breast cancer from coming back in some people with HER2-positive, early breast cancer.

5. Other targeted therapy medications for early breast cancer

Targeted therapy medications for early breast cancer work by targeting specific proteins in breast cancer cells. The main targeted therapies for early breast cancer are CDK4/6 inhibitors and PARP inhibitors.

Abemaciclib

Abemaciclib (Verzenio) is a CDK 4/6 inhibitor that’s approved to treat early breast cancer that’s spread to the lymph nodes and is considered HR+, HER2-negative. It works by blocking cyclin-dependent kinases (CDKs), which are proteins found inside HR+ breast cancer cells. By blocking CDKs, breast cancer cells stop dividing and are pushed into a state of “permanent sleep,” called senescence.

Abemaciclib is an oral pill that’s typically taken twice daily for 2 years in combination with hormone therapy. It’s usually given after surgery.

Olaparib

Olaparib (Lynparza) is a PARP inhibitor approved to treat early breast cancer that’s HER2-negative. PARP inhibitors block PARP proteins, which normally help repair DNA in cells. By blocking these proteins, cancer cell DNA isn't able to be repaired and the cancer cells die off.

However, olaparib has some prerequisites. It can only be given to people with a BRCA mutation who are at a higher risk of their breast cancer coming back. BRCA mutations are a type of inherited gene mutation that can raise your risk of developing breast cancer. What’s more, it's only an option for people who have already received surgery and chemotherapy.

Olaparib is an oral pill that's typically taken as 2 tablets twice daily for a year. It's usually taken after completing chemotherapy and can be taken at the same time as hormone therapy.

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Written by:

Sonja Jacobsen, PharmD, BCPS, BCOP

Sonja Jacobsen, PharmD, BCPS, BCOP,  is a clinical oncology pharmacy specialist currently practicing in Seattle. She has been practicing as a pharmacist since 2015 and is licensed to practice in Washington state and North Carolina.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Nicholas McAndrew, MD, MSCE

Dr. Nicholas McAndrew is a hematologist oncologist at the UCLA David Geffen School of Medicine in Los Angeles. Dr. McAndrew received his medical degree from the Perelman School of Medicine at the University of Pennsylvania, and completed both his internal medicine residency and his hematology/oncology fellowship at the Hospital of the University of Pennsylvania.

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