Skip to main content
An official website of the United States government

Participate in Cancer Prevention Trials

Assortment of healthy fruits, vegetables, and tea.

Some prevention studies test lifestyle changes to lower cancer risk such such as switching to a healthy diet.

What are cancer prevention studies?

Cancer prevention studies are research studies involving healthy people. In most prevention studies, the people who take part do not have cancer but are at high risk for it. Or they have had cancer and are at high risk for cancer coming back. These studies test whether certain medicines or behaviors may reduce someone’s risk of cancer in the future. 

What to expect

Cancer prevention interventions available today because of research.

Some prevention studies test lifestyle changes that scientists think may lower cancer risk. If you are in such a study, you might be asked to add something to your diet, follow a special diet, or add a physical activity.  

Some prevention studies might include surgery. Other prevention studies test whether medicines or other treatments lower cancer risk. If you are in such a study, you might be asked to take a 

  • medicine
  • vaccine or other substance that stimulates the immune system 
  • dietary supplement (such as a vitamin or mineral) 
  • combination of the above

In some cancer prevention studies, people are assigned by chance to different groups that make different lifestyle changes or take different medicines. The groups are then followed over time and compared to see if they differ in cancer cases. The process of assigning people to groups by chance is called randomization. Learn more about how randomization works in clinical trials.    

In other prevention studies, researchers look for biomarkers of possible cancer in the future rather than following participants for many years to see if they actually get cancer. Changes in biomarkers can happen quickly, helping researchers decide if a medicine is worthy of further study in larger cancer prevention studies.  

How long are prevention studies?

How long you take part in a prevention study depends on how the study was designed. Some, such as small trials looking at biomarkers, require you to take part for short periods of time, such as a few weeks. And others may go on for a few years. 

Many studies also include a follow-up period once you have finished taking the medicine or doing the behavior you were assigned. During the follow-up period, you may be asked to fill out surveys or visit the study site for exams. Follow-up may last a few weeks, months, or years.

Representative on a headset helping a patient who has called in for assistance

Have Questions About Cancer Prevention Studies?

Connect with our cancer information specialists.

Phone: 1-800-4-CANCER 
Chat: LiveHelp
Email: NCIinfo@nih.gov

Available Monday–Friday 9:00 a.m. to 9:00 p.m. ET.

Possible risks and benefits

The risks you may face will depend on what the cancer prevention study is testing. Risks may include side effects from medicines, supplements, or vaccines, or problems caused by surgery or other screening procedures.

A benefit to taking part in a prevention study is taking an active role in your own future health. You are also helping others who may avoid getting cancer in the future. Other benefits may include regular visits with a health care provider within the study and a chance that you may lower your risk of getting cancer.

Your rights

The study staff will talk with you before you join and tell you all about the study. They will explain: 

  • why the study is being done  
  • what will happen during the study 
  • what side effects you may have  
  • what to do if you have side effects 
  • how the study may affect your daily life  
  • that you can leave the study at any time 

Once you understand the study and decide to take part, you will be asked to sign a consent form. But even after you sign the form, you can change your mind and leave at any time. Learn more about informed consent in clinical trials.

Costs and expenses

Cancer prevention studies do have costs. Your health insurance may pay for some costs if they are part of usual care that you would receive if you weren’t in the study. The study may cover other costs, such as tests you have or the medicines you take as part of the trial. Or they may reimburse you for out-of-pocket costs, such as parking.  

Being in a prevention study takes time. So, you may have costs for travel, child care, and time away from work to take part. 

Before you decide to join a prevention study, it is a good idea to ask the study team for details on all costs and which ones you might be required to pay. Also be sure to ask how often you are required to visit the study site in person and over what period of time. 

Join a study

Connect for Cancer Prevention Study >

This study is for people ages 30-70 without a history of a cancer at the time of enrollment and a member of certain healthcare systems. Participants are asked to donate saliva and other samples and to answer health questions over time. 

FORTE Colorectal Cancer Prevention Trial >

This study is for people 50-69 who have had a complete screening colonoscopy within the past 4 years and were found to have one or two small, noncancerous polyps. FORTE will randomly assign eligible participants to repeat colonoscopies at 5 and 10 years or just at 10 years.

  • Updated:

If you would like to reproduce some or all of this content, see Reuse of NCI Information for guidance about copyright and permissions. In the case of permitted digital reproduction, please credit the National Cancer Institute as the source and link to the original NCI product using the original product's title; e.g., “Participate in Cancer Prevention Trials was originally published by the National Cancer Institute.”

Email