Over the past 40 years, breast cancer treatment has greatly improved due to lessons learned through clinical trials. Clinical trials test the safety and benefits of new treatments, diagnostic methods, and screening tests.

People volunteer to take part in these research studies. Those who join clinical trials help further the knowledge base that helps improve breast cancer care.

Clinical trials take place across the country and around the world in many types of medical centers and hospitals. Dedicated physicians, researchers, and other health professionals, as well as hospitals, medical research centers, and funders, are all key to clinical trials. However, the participants are most important.

To see if you or a loved one are eligible for an open clinical trial, please visit BreastCancerTrials.org or the National Cancer Institute clinical trials website. Other options are included at the bottom of this page.

Types of Cancer Treatment Trials

There are four main types of clinical trials for new breast cancer treatments.

  1. Phase I trials study whether a new treatment is safe to use over a range of doses. The treatment may be given to people with different types of cancer.
  2. Phase II trials study how well a treatment works for a certain cancer, such as breast cancer. These trials may include between 25-100 people.
  3. Phase III trials study how well a new treatment works compared to the standard treatment. People are randomized to get either the new or standard treatment; they do not choose which treatment they get. This ensures the study results reflect the true benefits and risks of the new treatment.
  4. Phase IV trials study the long-term side effects of treatments or answer new questions about treatment. They are done after a new breast cancer treatment is approved by the U.S. Food and Drug Administration (FDA-Approved).


If you have breast cancer, we encourage you to join a clinical trial. Clinical trials offer the chance to try new treatments and possibly benefit from them.

Some people worry they will get a placebo instead of an effective treatment in a clinical trial. However, placebos aren’t used in breast cancer clinical trials and aren’t commonly used in other cancer trials.

Most often in breast cancer treatment clinical trials, you will get either the new treatment or the standard treatment. Even if you don’t get the new drug or new therapy, your breast cancer will be treated the same as if you weren’t in the trial.

Sometimes in a non-metastatic breast cancer trial, you may get the standard treatment plus a placebo rather than the standard treatment plus the new treatment being studied. Metastatic breast cancer trials never use placebos. Your health care provider or the clinical research staff can tell you if there’s a placebo in the study, but they cannot tell you if you will receive it or not.

Possible Drawbacks

The location, side effects, and financial issues can create drawbacks for someone to participant in a certain clinical trial.

  • Location: Where you live may be a factor in choosing to join a clinical trial. Some trials are done at only one location, while others are done in many places across the country. Therefore, there may not be a clinical trial right for you in your area.
  • Side effects: The risks of a new treatment may not be fully understood, so there may be unexpected side effects. Testing limits these risks as much as possible, but all side effects of a new treatment are often not known until after long-term testing and follow-up.
  • Financial issues: The cost of a new treatment or test being studied is usually paid for by the clinical trial. Out-of-pocket costs for most clinical trials are the same as those for standard treatment.
    • The Affordable Care Act requires insurance companies to cover standard care costs related to a clinical trial that aren’t covered by the trial. Before enrolling in a clinical trial, talk with your insurance provider and find out exactly which costs are covered or not covered.

Process for Enrolling in a Clinical Trial

Before you join a clinical trial, discuss the risks and benefits with your health care provider. There may be a research nurse or coordinator from the clinical trial who can give you more information about the study.

Find a list of questions to ask you provider and/or research staff about joining a clinical trial.

All clinical trials have guidelines for who can join the study. Guidelines vary from study to study and may be based on type and stage of breast cancer, past treatments for breast cancer, and other medical conditions.

Most clinical trials are designed for select groups of people, so it’s important to find a trial that fits your situation.

If you and your health care provider decide a clinical trial is a good option for you, your provider should put you in touch with a research nurse or coordinator from the trial. This person will guide you through the enrollment process, including a review of the study protocols. After review of the study protocols, you will be asked to sign a consent form.

Being in a clinical trial is voluntary. You can leave a trial at any time for any reason. The consent forms give your permission to join the study and does not force you to stay in the study.

Learn more about clinical trials.

Find information about current clinical trials on the following websites:

If you or a loved one have exhausted treatment options and are not eligible for clinical trials, the Expanded Access Navigator may offer a chance to access investigational treatments not approved by the FDA.