Cancer: Clinical Trials

What are clinical trials?

Clinical trials are research studies in which people help health care providers find ways to improve health and cancer care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose, or treat cancer.

What are the different types of clinical trials?

There are several types of trials.

Treatment trials test new combinations of treatments, new cancer drugs, new approaches to surgery or radiation therapy, or new methods such as gene therapy.
Prevention trials test new ways to possibly lower the risk of cancer, such as medicines, vitamins, minerals, or other supplements.
Screening trials test the best way to find cancer, especially in its early stages.
Quality of life trials (also called supportive care trials) explore ways to improve comfort and quality of life for people who have cancer.

What are the phases of clinical trials of a new drug?

Most research that involves the testing of a new drug moves ahead in a series of steps called phases. There are usually 3 phases:

Phase I trials: These first studies test different ways to take a new drug, different dosages, and the side effects of the drug. A phase I trial usually enrolls only a small number of people.
Phase II trials: A phase II trial continues to test the safety of a drug, and begins to evaluate how well the new drug works.
Phase III trials: These studies compare a new drug with the current standard treatment. Participants are usually randomly assigned to either the group receiving the standard treatment or the group receiving the new treatment. (This is called randomization.) Phase III trials often enroll large numbers of people. They may be conducted at many doctors' offices, clinics, and cancer centers nationwide.

What happens during a trial?

If you decide to take part in a trial, you will work with a research team. Team members may include doctors, nurses, social workers, dietitians, and other health care providers. They will give you specific instructions about the study, provide your care, and monitor your health carefully during the study.

Participating in a trial may mean that you might have more tests and doctor visits than you would if you were not in the study. Team members also may continue to stay in contact with you after the trial ends. To make the trial results as reliable as possible, it is important for participants to follow the research team's instructions. That means carefully following the schedule for all doctor visits and tests, taking medicines on time, and completing logs or answering questionnaires.

What are the potential risks and benefits of clinical trials?

Some of the potential benefits are:

health care provided by leading doctors in the field of cancer research
access to new treatments or new drugs before they are widely available
close monitoring of your health for any side effects
a chance to make a valuable contribution to cancer research.

The potential risks include:

New drugs and procedures may have side effects or risks unknown to the researchers.
New drugs and procedures may not help, or they may not work as well as other treatments.
Even if a new treatment has benefits, it may not work for you.

How are participants protected?

The government has a system designed to protect you when you take part in a study. Before a government-funded clinical trial can begin, the trial plan (also called a protocol) must be approved. During the trial, review committees make sure that the plan is being followed and participants are being protected.

Regulations require researchers to tell you all about a study's treatments, tests, and possible benefits and risks before you decide to join the trial. This process is called informed consent.

What happens when a clinical trial is over?

After a phase I or phase II trial is completed, the researchers look carefully at the data collected during the trial and decide whether to:

Move on to the next testing phase with the treatment, or
Stop testing the treatment because it is not safe or effective.

When the analysis of a phase I, phase II, or phase III trial is complete, the researchers will inform the medical community and the public of the study results. In most cases, the results of trials are published in scientific or medical journals. Once a treatment or other intervention is proven safe and effective in a clinical trial, it may become the new standard of practice.

How do I know if I can be part of a clinical trial?

Each study has its own guidelines for who can take part, called eligibility criteria. Eligibility criteria for a treatment trial might be:

a particular type and stage of cancer
age
gender
previous treatments you have had.

To find out if you are eligible for a particular study, talk to your health care provider or the provider in charge of enrolling people in the study.

Should I take part in a clinical trial?

Only you can make the decision about whether or not to participate in a clinical trial. Before you make your decision, you should:

Learn as much as possible about your disease and the trials that are available to you.
Talk about this information and how you feel about it with your health care provider, family members, and friends.

When you talk with your health care provider, some of the questions you may want to ask are:

What is the purpose of the trial?
What tests and treatments are involved?
How long will the study last?
What side effects can I expect?
How will the side effects be managed?
For what costs will I be responsible?
What happens if I want to end my participation in the study?
Will my participating in the clinical trial decrease my chances of survival?

For more information, contact:

American Cancer Society (800-ACS-2345, http://www.cancer.org)
National Cancer Institute (800-4-CANCER, http://www.cancer.gov).

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File CNC3515F.HTM Release 9.0/2006