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Clinical trials

Clinical trials are research studies that test new ways to prevent, detect, treat or manage cancer or other diseases. Clinical trials provide information about the safety and effectiveness of new approaches to see if they should become widely available. Most of the standard cancer treatments used today were first shown to be effective through clinical trials.

Participation in a clinical trial may be an option for a person with cancer or someone at risk for developing cancer. People decide for themselves whether or not they want to participate in a clinical trial.

The importance of clinical trials

Clinical trials add to the progress that is being made against cancer. They answer important scientific questions and lead to future research. Many people with cancer are now living longer because of progress made through clinical trials.

Findings from past clinical trials have led to:

  • new and more effective drugs for specific types of cancer
  • drugs with fewer side effects
  • less invasive methods of surgery

Types and phases

There are many different types of clinical trials, including trials for prevention, screening and early detection, diagnosis, treatment and supportive care.

Clinical trials for new treatments involve several steps, called phases. Each phase of a clinical trial answers a different question about the disease and its treatment.

Components of a clinical trial

Clinical trials follow very strict procedures and ethical standards that protect the participants' health, safety and privacy. Each trial has several components, including its own protocol (action plan) and criteria for eligibility. People considering a clinical trial should be given enough information about the study (its components) to make an informed and educated decision about taking part. This process is called informed consent.

Benefits and risks

Clinical trials are carefully designed to have as few risks and as many benefits as possible for everyone who takes part. But each clinical trial offers its own possible benefits and risks. It is important to discuss these with your doctor.

Protection of participants

Government and international regulations and policies are in place to make sure that research involving people is done according to strict scientific and ethical guidelines. Clinical trial protocols are reviewed by a panel of at least 5 people at the hospital, clinic or university before the trial begins. Many clinical trials also require Health Canada’s approval. The panel, called a Research Ethics Board (REB), includes doctors, scientists and members of the general public. REBs help to protect the people who take part in a clinical trial. They also ensure that the trial is well designed, legal and ethical, and that it does not involve unnecessary risks.


A clinical trial usually takes place in the same location where standard cancer treatment is given – cancer centres, hospitals, clinics or doctors' offices. While some trials enrol people at 1 or 2 locations, a large clinical trial may involve thousands of people at hundreds of locations across the country or around the world. If a person lives in a small town or rural area, they may need to travel to a larger city to participate in the trial and take follow-up tests.

The research team

Clinical trial teams are made up of doctors, nurses, pharmacists, research assistants and other healthcare professionals. A clinical research associate or clinical research nurse on the team is available to help support people during treatment. This includes monitoring their health during the clinical trial, helping them understand what will happen during the clinical trial and answering any questions they may have.

Thinking about taking part in a clinical trial

There are many reasons why someone may choose to take part in a clinical trial. Most people who take part in clinical trials do so for personal reasons. They may want a chance to feel better or even to live longer. Other participants feel satisfied knowing they may be helping others with cancer, both now and in the future. Before deciding whether a clinical trial is an option for you or someone you care about, it’s important to learn all you can. While a clinical trial may be a good choice for some people with cancer, it may not be the best choice for others. If you are thinking of participating in a clinical trial, talk to your doctor or healthcare team so you can make the best choice for you.

See a list of questions to ask your doctor about clinical trials.

Sources of clinical trial information

For a current list of clinical trials, try the following websites:

Canadian Cancer Trials

(Clinical trials in all Canadian provinces)

National Cancer Institute

(Clinical trials in Canada, United States and around the world)

Please note that the information on clinical trials websites is often developed for researchers and may include medical language that can be difficult to understand. You may also want to ask your doctor about privately funded trials or those funded by drug companies that may not be listed on these websites.

If you do not have access to the Internet or have questions about clinical trials currently being conducted in Canada, please contact the Canadian Cancer Society's Cancer Information Service toll-free at 1 888 939-3333.


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