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Neoadjuvant (Preoperative) Therapies



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What is neoadjuvant therapy?

In select cases, treatment with chemotherapy, targeted therapy or hormone therapy may be given before breast surgery. When treatment is given before surgery, it is called neoadjuvant (NEE-oh-A-joo-vant) therapy.  

Neoadjuvant chemotherapy and hormone therapies are the same as those used after surgery (called adjuvant therapy). Some neoadjuvant targeted therapies are not used in the adjuvant setting.  

Neoadjuvant therapy does not increase survival (compared to adjuvant therapy). Rather, it changes the timing of treatment and can change surgical options. Sometimes, neoadjuvant therapy can shrink a tumor enough so that lumpectomy plus radiation therapy becomes an option to mastectomy [79,84]. 

Komen Perspectives 

Read our perspective on neoadjuvant chemotherapy (September 2010).* 

What to expect before neoadjuvant therapy

If you can have neoadjuvant therapy, you will have a needle biopsy to remove a small amount of tumor tissue. A radio-opaque clip is often placed in the tumor bed so the tumor can be found later when you have surgery.  

Tests on the biopsy tissue confirm your diagnosis and identify tumor characteristics, such as hormone receptor status and HER2/neu status. These factors determine the type(s) of neoadjuvant therapy that will offer the most benefit.  

Learn more about hormone receptor status and HER2/neu status.

Neoadjuvant chemotherapy

If you can have adjuvant (after surgery) chemotherapy, neoadjuvant chemotherapy may be an option as a first treatment [79]. For some women, it can change surgical options. Neoadjuvant chemotherapy can shrink a larger tumor enough so that lumpectomy becomes an option to mastectomy [79,84].

Most tumors respond to neoadjuvant chemotherapy. If a tumor does not respond to one chemotherapy drug regimen, the combination of drugs may be changed or it may be best to proceed with surgery.

Learn more about chemotherapy.

Types of neoadjuvant chemotherapy regimens

Neoadjuvant chemotherapy regimens are the same as the standard regimens used after surgery (adjuvant chemotherapy). Most are anthracycline- and taxane-based therapies. For HER2/neu-positive (HER2-positive) tumors, neoadjuvant therapy usually includes trastuzumab in combination with pertuzumab (learn more).

Learn more about chemotherapy drugs.

Learn more about HER2/neu status.

Pathologic response

When a person has neoadjuvant therapy, a pathologist checks the breast tissue removed during surgery for a pathologic response. Pathologic response describes how much of the tumor is left in the breast and lymph nodes after neoadjuvant therapy.

In some cases, neoadjuvant therapy will shrink the tumor so much that the pathologist cannot find any remaining cancer in the tissue removed during surgery. This is called a pathologic complete response (pCR).

A pCR can give some information about prognosis, but it does not change your treatment plan. Although a pCR is encouraging, it does not mean the cancer will never return. It’s also important to keep in mind that many people who do not have a pCR will still do very well.

pCR rates to neoadjuvant chemotherapy are highest among women with [85]:

  • High grade tumors
  • Hormone receptor-negative (estrogen receptor-negative (ER-negative) and/or progesterone receptor-negative (PR-negative)) tumors
  • HER2-positive tumors (when the neoadjuvant treatment plan includes trastuzumab and pertuzumab)

However, neoadjuvant chemotherapy can be effective in treating tumors of any grade and hormone receptor status.

Learn more about tumor grade.

Learn more about hormone receptor status and HER2/neu status.

Recurrence and survival with neoadjuvant chemotherapy

A meta-analysis that combined the results of eight studies found no difference in rates of breast cancer recurrence or overall survival in women who had neoadjuvant chemotherapy versus those who had adjuvant chemotherapy [84].

One large study looked at rates of breast cancer recurrence 10 years after treatment with neoadjuvant therapy. About 10 percent of the women who were able to have lumpectomy plus radiation therapy instead of mastectomy had a recurrence compared to about 13 percent of those who had mastectomy (with no radiation therapy) [86].

Learn more about lumpectomy versus mastectomy and survival.                      


For a summary of research studies on neoadjuvant chemotherapy, visit the Breast Cancer Research section.

Neoadjuvant hormone therapy

Neoadjuvant hormone therapy (with tamoxifen or an aromatase inhibitor) is an option for some women with hormone receptor-positive (ER-positive and/or PR-positive) breast cancer [79]. Like neoadjuvant chemotherapy, neoadjuvant hormone therapy can shrink a tumor enough that lumpectomy becomes an option to mastectomy [79,87].  

Although neoadjuvant hormone therapy is not often given in the U.S., it may have a role in the treatment of women who are not candidates for chemotherapy due to other health problems or advanced age. It may also be an option for women with:

  • ER-positive and PR-positive tumors
  • Low grade tumors
  • Invasive lobular breast cancer 


For a summary of research studies on neoadjuvant hormone therapy, visit the Breast Cancer Research section.

Most young women with large tumors are treated with chemotherapy rather than hormone therapy, even if their tumors are ER-positive. 

Learn more about hormone therapy.  

Learn more about chemotherapy.  

Learn more about hormone receptor status.  

Learn more about tumor grade.  

Learn more about lobular and ductal invasive breast cancer.  

Neoadjuvant therapy for HER2-positive breast cancers

If you have HER2-positive breast cancer, neoadjuvant trastuzumab (Herceptin) and pertuzumab (Perjeta) may be added to your neoadjuvant chemotherapy [79,88]. If you have neoadjuvant trastuzumab, you will likely also have trastuzumab after surgery (adjuvant trastuzumab). However, pertuzumab is only used as a neoadjuvant therapy and is not given after surgery [88].  

Trastuzumab is not usually given at the same time as anthracycline-based chemotherapy, neither in the neoadjuvant nor the adjuvant setting.  

Other targeted therapy drugs are under study as neoadjuvant therapies for HER2-positive breast cancers.

Learn more about HER2/neu status and prognosis.  

Learn more about trastuzumab.

After neoadjuvant therapy ends

To check the response to neoadjuvant therapy, you may have several tests, including a clinical breast exam, a mammogram, a breast MRI and/or an ultrasound. Then, surgery is planned much in the same way as if you did not have neoadjuvant therapy.

Sentinel node biopsy and neoadjuvant therapy

A sentinel node biopsy will be done either before neoadjuvant therapy begins or after neoadjuvant therapy, at the time of your breast surgery. The sentinel node biopsy checks for cancer in the lymph nodes in the underarm area.  

It is unclear whether it is better to have a sentinel node biopsy before or after neoadjuvant therapy. There are pros and cons to each and the best timing is still under study [92-93]. You should discuss this with your surgeon before you start neoadjuvant therapy.

Treatment guidelines

Although the exact treatment for breast cancer varies from person to person, guidelines help ensure quality care. These guidelines are based on the latest research and the consensus of experts. The National Comprehensive Care Network (NCCN) and American Society of Clinical Oncology (ASCO) are two respected organizations that regularly update and post their guidelines online. The National Cancer Institute (NCI) also has overviews of treatment options.

*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date at this time.  

Updated 06/24/14


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