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What Are Clinical Trials?

Female health professional explaining medical information to middle-aged couple.

Talk with your doctor about clinical trials when you discuss treatment options. 

Credit: SDI Productions

Clinical trials are research studies that test how well new medical approaches work in people. 

What is the purpose of a clinical trial? 

Clinical trials test new ways to find, prevent, and treat cancer. They also help doctors improve the quality of life for people with cancer by testing ways to manage the side effects of cancer and its treatment. 

Why are clinical trials important?

Today, people are living longer lives thanks to results of past cancer clinical trials. When you take part in a clinical trial, you add to our knowledge about cancer and help improve cancer care for people in the future.

People join clinical trials for many reasons. People living with cancer often join trials because they want to help future patients. People with certain risk factors want to help doctors learn how to prevent cancer. Healthy volunteers want to help doctors learn how to find cancer early. 

People with cancer and healthy volunteers join trials to play a role in cancer research and move science forward to help others.  

What are the types of clinical trials?

Photo of Marsha Dukes an NCI Clinical Trial Participant

"I feel that as an African American we do not participate in programs that could BE and sometimes ARE beneficial to us. I hope by my participation this will encourage others African American women to be more open." —Marsha Dukes, NCI clinical trial participant

There are several types of cancer clinical trials. Each type of trial is designed to answer different research questions and will help researchers learn things that can help people in the future.

Treatment Trials 

Most cancer clinical trials are treatment studies that involve people who have cancer. These trials test new treatments or new ways of using existing treatments. Read more about cancer treatment trials. 

Prevention Trials 

Prevention trials are studies that look at ways to prevent cancer. In most prevention trials, the people who take part do not have cancer but are at high risk for developing it. Or they have had cancer and are at high risk for developing a new cancer. Continue reading about cancer prevention trials.

Screening Trials

The goal of cancer screening trials is to test ways to find cancer before it causes symptoms, when it may be easier to treat. Read more about cancer screening trials.

Supportive Care/Palliative Care Trials >

These trials look at ways to improve the quality of life of people with cancer, especially those who have side effects from cancer and its treatment. Learn more about supportive care trials

You can also compare the different types of cancer research studies and see examples of discoveries for each. 

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