Is a Breast Cancer Clinical Trial Right for You?

Medically Reviewed by Laura J. Martin, MD on February 18, 2023

The purpose of a breast cancer clinical trial is to find new and improved ways of treating the disease. These treatments could be a new drug, surgery, or an alternative medicine.

Researchers, usually doctors, compare the best available treatment and the new treatment.


Why Do Clinical Trials?

Clinical trials help doctors decide things like:

  • Is the treatment safe and effective?
  • Is the treatment potentially better than ones already available?
  • What are the side effects of the treatment?
  • Does the treatment have any risks?
  • How well does the treatment work?
  • What is the maximum tolerable dose of the drug?

Types of Clinical Trials

All clinical trials are done in phases, each designed to find out specific information. Each new phase of a clinical trial builds on information from previous stages.

Participants may be eligible for clinical trials in different phases, depending on their health. Most clinical trial participants take part in phase III.

Phase I clinical trials study the safety of the new breast cancer treatment. It determines what doses are safe to give and by which route -- by mouth, or injection into a vein or muscle -- and how often it should be given. Phase I clinical trials usually enroll a very small number of people.

Phase II clinical trials happen if the treatment is found to be safe in the phase I trial. Phase II studies look at whether the treatment is effective in people with advanced disease and in certain cancers. Phase II clinical trials generally involve fewer than 100 people.

Phase III clinical trials compare the new treatment with the standard treatment to determine which one is superior. These trials may include hundreds of people across the country. If a treatment does well in phase III studies, it may receive FDA approval for use.

Who Can Participate?

Each breast cancer clinical trial enrolls patients with certain conditions and symptoms. If you fit the guidelines for a trial, you may be able to participate.

You'll get tests to confirm that you're a good fit for the study.


You could get a treatment before it is widely available to the public. The treatment being studied may be more effective than the usual ones.

You can give researchers information they need to develop new procedures and introduce new treatment methods.

Your treatment costs may be less, since many of the tests and doctor visits that are directly related to the clinical trial may be paid for by the company or agency sponsoring the study. Be sure to discuss treatment costs with the doctors and nurses running the clinical trial.


Usually, not all of the risks and side effects of the new treatment are known at the beginning of the clinical trial. Most treatments have potential side effects. You'll be told of any known possible side effects before you join a clinical trial. You'll also find out about any side effects that have become known while you're in the trial.

If you participate, you may not receive the new treatment being studied. Many breast cancer clinical trials combine a new treatment with a current one, and they compare that combination to the current treatment alone. Participants are randomly assigned to receive either the new combination or the usual treatment. This will be explained to you before you decide to take part.

The new treatment may not work for you, even if it helps others.

Insurers don't always cover all of the costs associated with taking part in a clinical trial. Talk to your insurance provider before you decide to participate.

There may be inconveniences, such as more frequent testing, more time at the doctor's office, and travel commitments.

Is It Safe?

All breast cancer patients face a new world of medical terms and procedures. Fears and myths of "experimentation" or "being a guinea pig" are common concerns. Understanding what's involved may help you feel better about it.

The personal information gathered about you during the trial will remain confidential and will not be reported with your name attached.

Trial participants typically receive their care in the same places that the standard treatments are given -- in clinics or doctors' offices.

Participants will be watched closely, and data on their cases will be carefully recorded and reviewed and compared to those of others in the trial. You may have extra visits between treatments to make sure that there are no unexpected side effects.

Many safeguards are in place to look out for the welfare of volunteers. These safeguards can't guarantee that you won't have complications, but they try to reduce risk as much as possible. Clinical trials are overseen by an investigational review board.

If at any time during the study your doctor feels it's in your best interest to quit, you will be free to do so. And it won't in any way affect your ability to be treated in the future.

Joining a Study

Breast cancer clinical trial participants are willing volunteers. Even though patients may be asked by their doctors to take part in a clinical trial, it's up to individuals to make the decision.

Before you take part in any breast cancer research study, you will be asked to give “informed consent” to participate. “Informed” means that as a patient, you are given all available information so you can understand what is involved in a specific clinical trial. The doctors and nurses conducting the study will explain the treatment to you, including its possible benefits and risks.

You will be given an informed consent form to read and consider carefully. Before signing, find out as much as possible about the clinical trial, including what risks you may face. Ask the doctor or nurse to explain parts of the form or the trial that aren't clear.

If you decide to participate, you will sign the consent form. If you choose not to participate, that won't prevent you from getting other care that's available.

Your signature on the informed consent form does not bind you to the study. Even if you sign the form, you are free to leave the trial at any time to receive other available treatments.

The informed consent process is ongoing. After you agree to participate in a breast cancer clinical trial, you will continue to receive any new information about your treatment that may affect your willingness to stay in the trial.

Questions to Ask

  • What's the purpose of this trial?
  • What kinds of tests and treatments does it involve? How are these tests given?
  • What's likely to happen in my case with, or without, this new research treatment?
  • Are there standard treatment options for my case, and how does the study compare with them?
  • How could being a part of the trial affect my daily life?
  • What side effects can I expect? (Remember: There can also be side effects from standard treatments and from the disease itself.)
  • How long will the trial last?
  • Will it require extra time on my part?
  • Will I have to be hospitalized? If so, how often and for how long?
  • If I choose to withdraw from the study, will my care be affected? Will I need to change doctors?