Neoadjuvant chemotherapy is a course of chemotherapy that’s given before your primary treatment, which is often surgery.

Neoadjuvant chemotherapy specifically refers to chemotherapy administered before your primary treatment, which may be surgery or radiation therapy. It can help make surgery more effective or allow surgeons to use a less extensive procedure.

Read on to learn more about neoadjuvant chemotherapy, including when it’s used, its potential benefits, and which cancers it’s most used to treat.

Neoadjuvant chemotherapy is given before your primary treatment. It may be included in your treatment when research suggests that adding an initial round of chemotherapy improves outcomes.

Most often, neoadjuvant chemotherapy is administered before surgery to improve the chances of removing all your cancer cells. It may also allow doctors to perform less extensive surgery than they would otherwise need.

Chemotherapy can damage healthy cells in your body and cause side effects. Doctors typically only administer neoadjuvant chemotherapy when the potential benefits are thought to outweigh the risks.

Neoadjuvant chemotherapy is often used to treat breast cancer. It is sometimes used alone or with immunotherapy or targeted therapies to treat other cancers, including:

Neoadjuvant chemotherapy and breast cancer

Neoadjuvant chemotherapy has been increasingly used as a treatment for breast cancer before surgery. Neoadjuvant chemotherapy may be used:

  • to shrink cancers too big to initially be removed with surgery
  • for cancers that affect many lymph nodes
  • to treat inflammatory breast cancers

This pre-surgical treatment is often used to treat triple-negative breast cancer or HER2-positive breast cancer.

According to the American Cancer Society (ACS), drugs that are commonly used for breast cancer include:

Not all people benefit from neoadjuvant chemotherapy. Researchers are still looking into who may benefit and who doesn’t.

The protocol for neoadjuvant chemotherapy varies depending on the type of cancer being treated.

According to the American Society of Breast Surgeons, neoadjuvant chemotherapy is usually administered preoperatively over 3 to 6 months when used to treat breast cancer. It’s often administered in four cycles, but you may receive more or less.

For example, in a phase 3 clinical trial, people with stage 2 or stage 3 triple-negative breast cancer received four cycles of 200 milligrams of pembrolizumab plus paclitaxel and carboplatin every 3 weeks or a placebo plus paclitaxel and carboplatin every 3 weeks.

The group receiving pembrolizumab plus neoadjuvant chemotherapy had better overall survival rates compared to the group only receiving neoadjuvant chemotherapy.

Neoadjuvant chemotherapy can potentially help shrink the cancer before your primary treatment. This may make your cancer easier to treat or allow a surgeon to use a less extensive surgical procedure.

Some cancers, such as early stage triple-negative breast cancer or HER2-positive breast cancer, have a better survival rate when neoadjuvant chemotherapy is administered.

Receiving chemotherapy drugs early in your treatment can also help doctors understand whether your cancer will respond to these drugs. If your cancer doesn’t, they may give you other drugs instead.

Getting chemotherapy before surgery can also give some people extra time to get genetic testing to look for particular markers that may influence treatment decisions.

The effectiveness of neoadjuvant chemotherapy depends on the type of cancer being treated.

In recent years, there’s been more of a shift toward treating breast cancer with neoadjuvant chemotherapy relative to administering chemotherapy after surgery.

In a 2022 study, researchers reviewed treatment records from over 3,000 people in one cancer center. The results indicated that the survival rates were similar among people who had chemotherapy before and after surgery.

A combination of fluoropyrimidine with or without oxaliplatin is often administered as a neoadjuvant chemotherapy to treat colon cancer, but its effectiveness isn’t well established.

Adjuvant chemotherapy is chemotherapy that you receive after your primary treatment. Its goal is to lower the chance that the cancer returns and to destroy any cancer cells that remain after surgery.

In some cases, you may receive both neoadjuvant and adjuvant chemotherapy. For example, if your doctor still sees cancer cells after you receive treatment with neoadjuvant chemotherapy and surgery, they may recommend more chemotherapy to destroy the remaining cells.

Neoadjuvant chemotherapy is administered before your primary treatment. It’s often used to treat breast cancer but is also sometimes used to treat other cancers such as prostate, colon, and lung cancer.

Your doctor can help you understand whether you may benefit from neoadjuvant chemotherapy.

Not everyone has improved outcomes with the addition of neoadjuvant chemotherapy. Factors such as your cancer stage and certain gene mutations may influence whether your doctors recommend neoadjuvant chemotherapy to you.