Clinical Trials

What is a clinical trial?

A clinical trial is a research study that tests new treatments, therapies, or procedures in people. These trials help determine whether a new treatment is safe and effective. Clinical trials are important for improving medical knowledge, especially for conditions like cancer.

Before a new treatment is tested in people, researchers do laboratory and animal studies to learn more about how the treatment might work. Once it reaches the clinical trial stage, it is carefully tested in a step-by-step process.

Most clinical trials include different groups:

• Treatment group: This group receives the new treatment or therapy being tested
• Control group: This group receives the current standard treatment or a placebo, depending on how the study is designed.

People are often placed into groups randomly. This is called randomization and helps ensure the results are fair and unbiased. In some trials, neither the participant nor the healthcare team knows which group the participant is in. This is called a blinded or double-blind study.

Regardless of the group, you will always receive some form of treatment — either the current standard of care or the new treatment being tested — but you will not be able to choose which one you get.

For people living with metastatic breast cancer (MBC), joining a clinical trial may provide early access to a promising treatment. It’s also a way to contribute to research that could improve care for others living with this disease.

Throughout the trial, participants are closely monitored by healthcare professionals. The trial follows a detailed plan called a protocol, which outlines how the study will be conducted, including how many people are involved, what tests are done, and how results are measured.

Each trial also has phases that test different things, such as safety (Phase 1), effectiveness (Phase 2), comparison to current treatments (Phase 3), and long-term effects (Phase 4).

Before joining a trial, you’ll go through a process called informed consent, where the research team explains the purpose of the study, what’s involved and what to expect.  

Types of clinical trials

There are several types of clinical trials for breast cancer treatment:

• Treatment Trials: Test new treatments or therapies
• Prevention Trials: Explore ways to prevent breast cancer
• Screening Trials: Develop methods for earlier detection
• Quality of Life Trials: Focus on improving patient well-being

Benefits of participating in a clinical trial

• Early Access: Participants may receive promising treatments before they’re widely available
• Close Monitoring: Participants are carefully followed by a medical team throughout the trial
• Contribute to Research: Participation can help advance breast cancer treatment for future patients

Risks of participating in a clinical trial

• Unknown side effects: New treatments may have unexpected or unknown side effects
• Increased medical visits: Clinical trials often involve more visits, tests, and procedures
• Uncertainty of results: There’s no guarantee that the experimental treatment will work or be better than current treatments

Participation is always voluntary. You can leave a trial at any time without affecting the quality of your care.

Finding a clinical trial in Canada

If you're interested in participating in a clinical trial, speak with your healthcare team and explore resources such as:

• Clinical Trials Finder - Clinical Trials Ontario
• Search for a Clinical Trial in Oncology - OncoQuébec
• McPeak-Sirois Group for Clinical Research in Breast Cancer
• Clinical Trials Navigator - Canadian Cancer Clinical Trials Network
• Canadian Precision Oncology Trial Finder - Canadian Cancer Clinical Trials Network
• ClinicalTrials.gov
• Clinical trials | Canadian Cancer Society

For more information on how clinical trials work, visit:

• Questions & Experts: A Surgical Oncologist Answers Your Questions About Breast Cancer Clinical Trials
• CBCN Workshop: Deconstructing Clinical Trials
• It Starts With Me

Medical Review by Roochi Arora, MD, FRCPC, August 2025

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