Let's Talk About Breast Cancer Medication

Advancements in drug therapies have made it easier than ever to treat breast cancer. Learn more about the common meds available, and how they work.

by Sunny Sea Gold Health Writer

When you hear breast cancer medication, the first thing you likely think of is chemotherapy. It’s not the only option, however, and new developments in this area are setting the groundwork for promising treatments in the future. If you’re considering medication as part of your breast cancer treatment plan, here are some options you should know about.

Breast Cancer Medication

Our Pro Panel

We went to some of the nation’s top experts in breast cancer to bring you the most up-to-date information possible.

Zahi Mitri, M.D.

Zahi Mitri, M.D.

Breast Cancer Oncologist

The OHSU Knight Cancer Institute

Portland, OR

Jack Jacoub, M.D.

Jack Jacoub, M.D.

Medical Oncologist and Medical Director of MemorialCare Cancer Institute

Orange Coast Medical Center

Fountain Valley, CA

Jonathan Stegall, M.D.

Jonathan Stegall, M.D.

Medical Director

The Center for Advanced Medicine

Alpharetta, GA

Breast Cancer Medication
Frequently Asked Questions
How will I know which breast cancer medication is right for me?

Your cancer care team will work with you to figure out the best options. The current approach in treatment is to give you the least amount of medication necessary to have a positive outcome. That way, you’ll hopefully have fewer side effects.

What are the side effects of chemotherapy?

Nausea, mouth sores, hair loss, and brain fog are some of the most common side effects of chemo. The good news is that new medications have been developed that you can take along with chemotherapy to ease some of these issues.

What's the difference between local and systemic treatments?

Surgery and radiation are considered local treatments because they happen in and around the breast. Systemic treatments are medications that you take internally that are then spread throughout the body to fight cancer cells.

How long will I need hormone therapy for?

Typically, hormone therapy lasts anywhere between five and 10 years. To help you get the maximum benefit of this approach, your doctor may switch you from one medication to anther part-way through your treatment.

Every case of breast cancer is different, so your treatment plan will be unique to you. Along with the possibility of surgery and radiation (considered “local” treatments because they happen in and around the breast) your doctor might talk to you about “systemic” treatments, or medications that are taken internally and then spread throughout the body to fight cancer cells. Examples of these systemic treatments include:

  • Chemotherapy

  • IV drugs

  • Oral medications

Systemic therapies for breast cancer are becoming more precise and personalized. Which ones you’ll use will depends on your doctor’s analysis of detailed genetic and hormonal info, as well as additional testing of your tumor cells.

The goal with medication is to give you the least amount of drugs necessary for the most positive effect. Doctors call this “de-escalating” treatment, and it’s a new approach that aims to improve cure rates and lower the cancer recurrence risk without over-treating the patient. That’s good news since it saves you unnecessary side effects and longer-lasting complications associated with some medications.

With that in mind, here are some of the medication options you may want to consider.

Get the Full Story on Breast Cancer

What Type of Meds Will I Need for Breast Cancer?

If you have a lumpectomy or mastectomy, before or after surgery you also may need medication. Systemic therapies given before surgery are called neoadjuvant therapy, and their goal is to shrink or stop the tumor from growing.

Those given after surgery are called adjuvant therapy and they aim to prevent the tumor from re-emerging. Unfortunately, tumors can adapt to medications and stop responding—in those cases a doctor may switch you to a new drug or combination of drugs.

There are four main types of medication (or “systemic therapies”) used in treating breast cancer: chemotherapy, hormone therapy, targeted therapy, and immunotherapy.

How is Chemotherapy Used for Breast Cancer?

Although it’s a common type of medication for breast cancer, not everyone with breast cancer needs chemo. Testing of the tumor cells can help your doctor tell if chemotherapy will help.

The typical way to get chemo is through an IV infusion or injection at a clinic or doctor’s office that delivers the meds right to your bloodstream. In some cases, your doctor might recommend a pill version of the drug instead. Doses are given in bursts—or “cycles”—of a few weeks at a time so you can rest and recover from each treatment before having another.

The length of your chemo treatment will vary, but it often lasts anywhere from three to six months.

Common Breast Cancer Chemotherapy Drugs

There are many different chemotherapy medications that may be used to fight breast cancer. Which ones your doctor recommends will depend on the stage of cancer, size of the tumor, and other factors. These meds can be used by themselves or in combination with one or two other chemo drugs. Some chemotherapy medication classes used in treating breast cancer include:

  • Anthracyclines

  • Taxanes

  • Cyclophosphamide

  • Carboplatin

Side Effects of Chemotherapy

You probably know that chemotherapy can cause unpleasant side effects. That said, other new medications can be prescribed at the same time to help you feel better and make treatment easier. Some side effects of chemotherapy may include:

  • Nausea

  • Mouth sores

  • Hair loss

  • Higher risk of infections

  • Reduced appetite and/or weight loss

  • Brain fog or trouble with concentration and memory (often called “chemo brain”)

  • Fatigue. Sometimes this tiredness goes away once treatment ends, but it can be longer-lasting.

  • Nerve and other damage. Certain chemotherapy medications can damage your nerves, creating tingling and numbness. Some drugs—especially if used for long periods of time—can also damage cells of the heart.

  • Fertility issues. Some chemo drugs can cause younger women to go into premature menopause or become infertile. Women who want to have kids after treatment may choose to freeze their eggs before starting chemo.

How Does Hormone Therapy Work?

About two-thirds of breast cancer tumors rely on the hormones estrogen or progesterone to grow. To help lessen or cut off the supply of these hormones to the tumor, your doctor may prescribe hormone therapy drugs.

These medications, which are usually taken for between five and 10 years, are generally successful at treating the disease and keeping the cancer from growing back. In some cases, you will take one type of hormone therapy drug for the first couple of years, and then switch to another type maximize your treatment benefits.

Common Breast Cancer Hormone Therapy Drugs

There are two main categories of hormone therapy drugs used to treat breast cancer. One type works by blocking estrogen receptors so that less estrogen can get into the breast tissues and/or tumor; the other type works by lowering estrogen levels in the body.

  • Estrogen receptor blockers. These drugs stop estrogen from linking up with cancer cells and driving them to grow and spread. The most commonly prescribed one is tamoxifen, a medication that is also used to help prevent breast cancer in high-risk women. Other estrogen receptor blockers that may be used in postmenopausal women and/or advanced cancers include:

    • Faslodex (fulvestrant)

    • Evista (raloxifene)

    • Fareston (toremifene)

  • Estrogen-lowering drugs. These medications lower the amount of estrogen that your body naturally makes in order to starve a hormone-dependent tumor of what it needs to grow. The most common of these drugs are aromatase inhibitors such as:

    • Femara (letrozole)

    • Arimidex (anastrazole)

    • Aromasin (exemestane)

Side Effects of Hormone Therapy

Depending on which type of hormonal therapy you receive, there may be different side effects. Side effects for estrogen receptor blockers include:

  • hot flashes

  • vaginal dryness

  • discharge or bleeding

  • cancer of the lining of the uterus (very rare)

  • cataracts (very rare)

  • blood clots (very rare)

Side effects for estrogen-lowering drugs include:

  • muscle and joint pain

  • hot flashes

  • vaginal dryness

  • increased risk for osteoporosis

  • increased risk of high cholesterol levels

  • mood swings

Learn About All Your Breast Cancer Treatment Options

Should I Get Targeted Therapy for Breast Cancer?

Medications known as targeted therapies work on specific proteins and genes in breast cancer tumors, such as the HER2/neu protein. Rather than killing cancer cells and other tissues in the way that chemotherapy can, targeted therapies typically don’t damage healthy cells as much.

There are many kinds of targeted therapy medications, which is good because everyone’s tumor is different. Which one you’ll get depends on what test results indicate about your tumor. Targeted therapies can be given as injections, IV infusions, or in pill form. How long you’ll take them depends on the specifics of your breast cancer, but some may be given for up to a year.

Common Breast Cancer Targeted Therapy Drugs

Scientists are developing a growing number of medications that can target different genes, proteins, and other factors in breast tumors. A few of the most common targeted drugs for breast cancer are those that work on HER2/neu-positive breast cancers. These include:

  • Herceptin (trastuzumab)

  • Perjeta (pertuzumab)

  • Nerlynx (neratinib)

  • Kadcyla (ado-trastuzumab emtansine)

Side Effects of Targeted Therapy Drugs

Because there are so many different targeted medications used to treat breast cancer, there are also many different potential side effects and the potential for longer-lasting damage. Some may include:

  • fatigue

  • hair loss

  • mouth sores

  • nausea

  • increased cholesterol or blood sugars

  • increased risk of infection

  • heart problems

What's the Deal With Immunotherapy?

Rather than targeting the cancer cells themselves the way chemotherapy does, immunotherapy drugs (sometimes called “biologics”) boost the immune system’s ability to recognize and kill breast cancer cells on its own.

Immunotherapy is an area of breast cancer treatment research that’s not quite as far along as research into hormonal or targeted medications. And at this point, hormonal and targeted therapies have generally been shown to be effective with fewer side effects for many cases of breast cancer than immunotherapy.

But in cases where more established treatments don’t help, your doctor may suggest a more experimental approach, and that’s often where immunotherapy comes in. More is being learned every year about the possible benefits of immunotherapies for certain breast cancer cases.

Common Breast Cancer Immunotherapy Drugs

As of 2019, there are just two immunotherapy medications approved by the Food and Drug Administration for use in breast cancer. They are:

  • Keytruda (pembrolizumab). This medication is FDA-approved for use in stage IV, or metastatic, cancers that have spread to other parts of the body.

  • Tecentriq (atezolizumab). This is an IV drug that blocks a protein called PD-L1 found on some tumor cells and helps immune cells recognize and attack them. It’s typically used for advanced, triple-negative breast cancers.

Side Effects of Immunotherapy Drugs

A few possible side effects of immunotherapy for breast cancer include:

  • skin reactions

  • diarrhea

  • weight changes

  • flu-like symptoms

Being diagnosed with breast cancer is stressful, but thanks to advancements in medications, there’s a really good chance you’ll be back to living your normal life faster than you think. To read more about the ins-and-outs of breast cancer, click here.

Sunny Sea Gold
Meet Our Writer
Sunny Sea Gold

Sunny is a health journalist with deep expertise in women's and children’s health who has written for some of the largest and most well-known print and digital publications in the United States. She’s also the author of the book Food: The Good Girl’s Drug, and writes essays and reported pieces on body image, eating disorders, parenthood, and mental health. She lives in Portland, OR, with her husband and two daughters.