Clinical Trial FAQs
Short, plain-language answers — each one linked to its official National Cancer Institute source.
Educational only — not medical advice. Cancer Explained does not recommend clinical trials or determine eligibility. Whether a clinical trial is appropriate for you depends on your diagnosis, test results, and treatment history — please discuss clinical trials with your oncology team.
The basics
What is a clinical trial?
A clinical trial is a research study that tests a new way to prevent, find, or treat cancer. People volunteer to take part, and what is learned helps care for future patients. Every trial follows a careful written plan and includes steps to protect the people who join.
Source: NCI: What Are Cancer Clinical Trials? (External — official resource)
How long do trials last?
There is no single answer. Some trials take weeks, while others follow people for months or years. The length depends on the study's questions and the type of trial. The team can tell you how long a particular study is expected to run and how often you would have visits.
Source: ClinicalTrials.gov: Learn About Studies (External — official resource)
Will I still receive standard treatment?
In most cancer treatment trials, everyone receives at least the standard of care, the treatment experts agree is best right now. A new approach is often tested next to it or added on top of it. You will not be denied proven care in order to take part. The trial's plan explains exactly what each group receives.
Source: NCI: What Are Cancer Clinical Trials? (External — official resource)
What is randomization?
In some trials, a computer places each person into a group by chance. This is called randomization, and it helps keep the comparison fair. Neither you nor your doctor picks your group, and your team still watches over you closely no matter which group you are in.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
What happens after a trial ends?
When a trial ends, the team may keep in touch to check on your health, and you return to care with your regular oncology team. Sometimes people can keep receiving a study treatment that helped them, depending on the study. The team can explain what to expect for your particular trial.
Source: ClinicalTrials.gov: Learn About Studies (External — official resource)
How are trial results used?
Results from clinical trials help doctors learn what works and what does not. Findings may be shared in medical journals and public databases and can shape care for future patients. Trials in the United States are often listed on ClinicalTrials.gov, where results may be posted over time.
Source: ClinicalTrials.gov: Learn About Studies (External — official resource)
Is my personal information kept private?
Trials have rules to protect your privacy. Your health information is handled carefully, and when results are shared they usually do not identify you by name. The consent process explains how your information will be used and kept safe, and you can ask the team about privacy before you join.
Source: NCI: Safety in Cancer Clinical Trials (External — official resource)
What is a protocol?
A protocol is the written plan for a clinical trial. It describes the study's purpose, who can join, what will happen, and how the team will keep people safe. Following the same plan at every site helps make the results reliable.
Source: ClinicalTrials.gov: Learn About Studies (External — official resource)
How do I bring up clinical trials with my doctor?
You can simply ask, "Could a clinical trial be an option for me?" It helps to write down your questions ahead of time and bring someone with you to the visit. Your oncology team can explain whether trials may fit your situation and help you find trustworthy listings.
Source: NCI: Cancer Clinical Trials (External — official resource)
What questions should I ask about a trial?
Good questions include what the study is testing, the possible benefits and risks, how often you would have visits, what costs you might face, and whether you would still receive standard care. Writing your questions down ahead of time can help. Our questions tool can help you build a list to bring to your team.
Source: NCI: Cancer Clinical Trials (External — official resource)
Safety, placebos & informed consent
Can I leave a trial at any time?
Yes. Taking part is always your choice, and you can leave a trial at any time, for any reason. Signing a consent form does not lock you in. It is a good idea to tell your care team if you plan to stop so they can help you do so safely.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
Are clinical trials safe?
Your safety is the top priority in a clinical trial. Trials follow a careful plan, and the team checks on you often with visits and tests. Outside groups, review boards, and written safety rules add more layers of protection. No treatment can be promised to be risk-free, so the team explains the known risks before you join.
Source: NCI: Safety in Cancer Clinical Trials (External — official resource)
Will I receive a placebo?
In cancer treatment trials, a placebo is rarely used alone. When a proven treatment already exists, it would not be right to leave people untreated. If a placebo is used, it is usually added to standard care, so one group gets standard care plus the new treatment and the other gets standard care plus a placebo. The trial's plan explains exactly how any placebo is used, and your team will tell you before you join.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
What is informed consent?
Informed consent is how you learn about a trial before deciding to join. The team explains the purpose, what will happen, the possible benefits, and the known risks, and you can ask questions and take your time. If you decide to join, you sign a consent form, but you can still leave the trial at any time.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
Finding & joining a trial
Who can join a clinical trial?
Each trial has rules about who can take part, called eligibility criteria. They may include the type and stage of cancer, past treatments, age, and overall health. Only the research team can decide whether a specific trial is a match for a specific person. Your oncology team can help you understand which trials, if any, may fit your situation.
Source: NCI: What Are Cancer Clinical Trials? (External — official resource)
Can children join clinical trials?
Yes. There are trials designed just for children, because childhood cancers differ from adult cancers. A parent or guardian gives permission, and older children are also asked whether they agree in words they can understand. The care team explains everything to the family.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
Can older adults join clinical trials?
Yes. Older adults can and do take part in clinical trials, and their involvement helps make sure results apply to people of all ages. Whether a trial is a fit depends on its eligibility criteria and your overall health, not age alone. Your oncology team can help you weigh the choice.
Source: NCI: Why Participate in Cancer Clinical Trials? (External — official resource)
Do I get paid to join a clinical trial?
Cancer treatment trials do not usually pay you to take part. Some studies offer help with certain costs, such as travel or parking. Ask the team whether any reimbursement is available and what costs you might be responsible for.
Source: NCI: Paying for Cancer Clinical Trials (External — official resource)
How can I find clinical trials?
You can search official listings, such as the NCI Clinical Trials Search and ClinicalTrials.gov, and your oncology team can help. These tools let you look by cancer type, age, and location. Finding a listing is a starting point for a conversation with your care team, not a recommendation.
Source: NCI Clinical Trials Search (External — official resource)
Costs, insurance & day-to-day logistics
Who pays for clinical trials?
Costs in a trial usually fall into two groups. Research costs, such as the study drug and extra tests done just for the study, are often covered by the study's sponsor. Routine care costs, the care you would get anyway, are often billed to insurance. Rules vary, so ask the study team and your insurer what will be covered before you join.
Source: NCI: Paying for Cancer Clinical Trials (External — official resource)
Will my insurance cover a clinical trial?
Insurance often covers routine care costs, the care you would receive anyway. Research costs, such as the study drug, are frequently covered by the study's sponsor. Coverage rules vary by plan and by state, so it is wise to check with both the study team and your insurer before you join.
Source: NCI: Paying for Cancer Clinical Trials (External — official resource)
Will I have to travel for a clinical trial?
Some trials are offered close to home, while others are only at certain hospitals or research centers. Travel and how often you need to visit vary by study. Ask the team about the schedule and whether any travel or lodging help is available.
Source: NCI: Cancer Clinical Trials (External — official resource)