What Is Neoadjuvant Chemotherapy for Breast Cancer?


When chemotherapy is your first treatment for cancer, it’s called ‘‘neoadjuvant therapy.’’ It’s often used for advanced breast cancer or large tumors that complicate surgery. But it has other equally important benefits.

When chemotherapy is the first step in your breast cancer treatment, it’s called “neoadjuvant therapy.” Neoadjuvant therapies are systemic therapies that come before a main treatment.

Because there are several kinds of breast cancer, not everyone receives the same treatment in the same order. Though neoadjuvant chemotherapy is a good option for some people with breast cancer, it’s not the best choice for everyone.

This article discusses neoadjuvant chemotherapy for breast cancer, when and how it’s used, and what you can expect from the treatment.

What is neoadjuvant chemotherapy?

You receive neoadjuvant chemotherapy for breast cancer before your main treatment. In breast cancer, the main treatment is likely to be:

Other treatments include hormone therapy and targeted therapies.

Neoadjuvant vs. adjuvant chemotherapy

Neoadjuvant therapy: Breast cancer typically requires more than one type of treatment. The primary treatment is usually surgery. When you have chemotherapy first, it’s called “neoadjuvant therapy” because it comes before the main treatment. The goal is to shrink the tumor. In some cases, this means you can have less extensive surgery. 

Adjuvant therapy: When you have chemotherapy after surgery, it’s an adjuvant therapy. It adds to the main treatment. The goal is to destroy the remaining cancer cells and reduce the risk of recurrence. Adjuvant systemic therapy is a common treatment for early-stage breast cancer. 

When is neoadjuvant chemotherapy used to treat breast cancer?

Neoadjuvant chemotherapy for breast cancer may be beneficial if you have:

There’s a lot to consider, so it comes down to a case-by-case decision. To figure out whether you’re a good candidate, your oncology team will consider any other health concerns you may have.

In addition to a clinical examination, some tests that can help inform the decision are:

These tests help determine key factors such as:

  • tumor type
  • grade (aggressiveness) 
  • whether the cancer has invaded the lymphatic or vascular system
  • whether the cancer has spread to distant organs/sites (if it has, then surgery is not an option)

In addition to deciding the order of treatments, this information can help determine which chemotherapy drugs are most likely to be effective.

What are the benefits of neoadjuvant chemotherapy?

If you’re not able to have surgery right away, neoadjuvant chemotherapy can get treatment started. This can help keep cancer from spreading before you’re ready for surgery.

And shrinking a large tumor can lower the risk of complications during surgery. 

Other potential benefits are:

  • Evaluating chemotherapy drugs: Your oncologist will monitor the size of the tumor. This makes it easier to see how well chemotherapy is working. You can quickly switch to a different drug if the tumor isn’t shrinking. 
  • Lowering risk of recurrence: Because chemotherapy is a systemic therapy, it can also kill cancer cells that may have entered the lymphatic or vascular system. This can lower the risk of recurrence.
  • Less invasive surgery: Shrinking the tumor may make it possible to have breast-conserving surgery rather than a mastectomy. In some cases, neoadjuvant chemotherapy may eliminate the need for surgery
  • Planning purposes: Starting with chemotherapy gives you more time for genetic testing and making decisions about breast cancer surgery and reconstructive surgery.

How is neoadjuvant chemotherapy for breast cancer given?

The specifics of chemotherapy vary from person to person. Aside from the timing, the basic procedures for neoadjuvant and adjuvant chemo are the same.

Chemo is given in cycles. One treatment, or infusion, is sometimes called a “round.” Most, if not all, neoadjuvant chemo regimens are given intravenously based on NCCN (National Comprehensive Cancer Network) guidelines.

Following an infusion of chemo, you have a rest period to allow your body to recover. The infusion and rest period is referred to as a “cycle.” Your next infusion begins a new cycle.

A single infusion can take several hours. It varies, but chemo cycles for breast cancer are usually 2 or 3 weeks long.

The number of infusions and the rest period length depend on the drug or combination of drugs and how well it works. If side effects are severe, you may need a longer rest before the next round. This can extend overall treatment time. 

Neoadjuvant chemo can last 3 to 6 months. Imaging tests will help evaluate the response. With a good response, you may be able to schedule surgery within a few weeks of your last cycle. 

What are the potential side effects of neoadjuvant chemotherapy?

Side effects from neoadjuvant and adjuvant chemotherapy are the same. Much depends on the specific drugs, doses, and number of cycles.

Although the list of potential side effects is long, you probably won’t have them all. Some side effects from chemo are:

  • fatigue
  • hair loss and nail changes
  • loss of appetite and weight changes
  • nausea and vomiting
  • diarrhea or constipation
  • mouth sores
  • easy bruising and bleeding
  • risk of infection
  • change in menstrual cycle
  • slight decrease in mental function, commonly known as “chemo brain”

Most of these side effects begin to fade when treatment ends. Some potential longer-term side effects may include: 

Immunotherapy may be given with neoadjuvant chemotherapy

It’s worth noting that immunotherapy, such as pembrolizumab (Keytruda), may be given along with neoadjuvant chemotherapy for some people. These drugs have a different list of side effects.

If you are prescribed immunotherapy and neoadjuvant chemotherapy, talk with your doctor about potential side effects and what to expect.

Does neoadjuvant chemotherapy improve the outlook of people with breast cancer?

Not everyone has a good response to neoadjuvant chemotherapy. You can have a partial response or no response. It’s also possible to have a complete response, meaning there’s no longer evidence of cancer. 

Research suggests that when compared with those whose tumors don’t respond to chemo, those with a complete response are more likely to:

  • have a long-term disease-free survival
  • better overall survival 

A recent phase 2 clinical trial involved 50 people with triple-negative or HER2-positive breast cancer. Trial participants had biopsies after finishing neoadjuvant chemotherapy. Results showed that 31 had a complete response. At a median follow-up of 26.4 months, there were no recurrences.

But the timing of chemotherapy is only one factor in breast cancer outlook. Other factors that influence outlook are: 

  • type of breast cancer
  • stage at diagnosis
  • tumor grade
  • previous treatment
  • overall health

Your oncologist can provide a more personal assessment based on your unique factors.


Neoadjuvant chemotherapy for breast cancer is typically given before your main treatment, which is usually surgery. In some cases, neoadjuvant chemotherapy can result in less invasive surgery.

Not everyone with breast cancer is a good candidate for neoadjuvant chemo. It may benefit those with a large primary tumor, regional spread, or certain types of cancer, such as inflammatory breast cancer.

Imaging tests and biopsy results can help determine whether neoadjuvant or adjuvant chemotherapy is better for you. 

Last medically reviewed on November 9, 2022

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Medically reviewed by Faith Selchick, DNP, AOCNP, Nursing, Oncology — By Ann Pietrangelo on November 9, 2022

Posted in: In Treatment, Treatment