Answering 10 Commonly Asked Questions About Cancer Clinical Trials

Nearly everything we know about cancer today- how to find it, treat it, and even prevent it- started with a scientific discovery that was tested in a clinical trial. The most effective chemotherapy drugs, screening tests, and treatments for managing symptoms are available today because of research studies made possible by volunteers. 

Still, many people aren’t sure what clinical trials involve, how they work, or know that they could be a part of one. 

Here, experts from the Herbert Irving Comprehensive Cancer Center (HICCC) cancer clinical trials team answer 10 of the most common—and often misunderstood—questions about how cancer clinical trials work, who they’re for, and why they matter. 

1. What is a cancer clinical trial?

A cancer clinical trial is a research study involving volunteers that helps doctors find better ways to detect, treat, and prevent cancer. 

Clinical trials are how we make progress in cancer care and research. Most new cancer treatments are studied for many years before they ever reach a clinical trial. First, researchers test them in the lab to see if they’re safe and show promise. Only after passing several stages of preclinical research can a treatment move into clinical trials with people.

2. What do clinical trials study?

Sometimes, clinical trials study a brand-new drug. Other times, it’s testing whether a treatment already in use for one cancer could work better for another. Trials might also explore better ways to manage side effects or improve patients’ quality of life.  

What they focus on depends on the type of trial—and the phase it’s in. Here’s a simple breakdown of the four main phases of clinical trials and the questions they seek to answer: 

• Phase I: Is the treatment safe? What dose should we use?
• Phase II: Does it work for this specific type of cancer?
• Phase III: Is it better than the current standard treatment?
• Phase IV: What are the long-term effects? (These happen after FDA approval.)

Each phase builds on the last. If a treatment isn’t safe or effective, it doesn’t move forward.

3. Do all clinical trials test new treatments?

No, clinical trials have different goals, and test different things, such as: 

• Cancer treatment trials: To learn which drugs and treatments are safe and work best and are better than the ones currently available. 
• Cancer prevention trials: To find new ways to prevent or find a disease, such as cancer. 
• Quality of life trials: To help make the lives of patients with a disease better and more comfortable during and after their treatment. 
• Diagnostic trials: To study new ways to understand an individual person’s disease. 
• Screening trials: To test the best way to detect cancer. 

4. When should I consider participating in a clinical trial?

A good time to discuss a clinical trial with your doctor is when you are first diagnosed with cancer. Some clinical trials are for patients as their first and only treatment, while others are for patients who did not respond to the first cancer treatment. 

Some trials are open to people who don’t have cancer at all- especially prevention or screening studies. 

5. What can I expect once I’m on a clinical trial? 

When you join a clinical trial, your doctor and the clinical trials team will guide your care, explain any risks, and monitor you closely during and after treatment. Some patients prefer being on a clinical trial because of the extra attention and support throughout your treatment. 

The trial's impact on your daily life depends on the type of study. Some involve taking a pill at home, while others—especially early-phase trials—may require hospital stays.  

After the trial ends, you’ll continue to be monitored through follow-up visits and tests. 

6. Why do people volunteer for clinical trials? 

There are many reasons people may choose to participate in a cancer clinical trial. Some choose to join to help add to our knowledge about cancer and improve treatments for all patients. Others may join because they have certain genetic risk factors and want to help researchers learn more—so future patients with similar risks can benefit. 

People with cancer who qualify for a clinical trial may choose to participate to get access to new treatments that aren’t yet widely available—especially if standard treatments are not effective for them. 

7. Do cancer clinical trials use a placebo drug? 

While this is a very common concern, placebos are rarely used in cancer treatment clinical trials, and never in place of standard care. 

If a placebo is part of a study, participants are told up front, and it’s only used when there is no existing standard treatment. You will always be fully informed and cared for throughout the study. 

8. How do I find a cancer clinical trial? 

Start by talking with your provider or oncology team. They can help connect you to trials that are right for your type of cancer and treatment history. 

You can also search for open trials on websites like clinicaltrials.gov or through cancer centers like the HICCC. 

9. Can I leave a clinical trial?

You can decide to stop the treatment at any time. Your clinical trials team will continue to provide care and monitor you whether or not you are in a study.  

Today's clinical trials are safer and more precise than ever, thanks to advances in cancer science and technology. 

In early-phase trials (like Phase I), researchers test very low doses of a new treatment and slowly increase the amount to find the safest dose possible. By the time a treatment reaches later-phase trials, doctors already have a good idea of what side effects to expect and how to manage them. 

Still, every person is different, and side effects can happen. That’s why patients in clinical trials are monitored very closely. You’ll have regular check-ins, lab tests, and extra support from a care team that knows the trial inside and out, including research nurses and specialists who track your health and help you through every step of the way. 

10. Why is it important for people to consider clinical trials? 

Being part of a clinical trial helps doctors learn if new drugs, devices, and procedures work on all people of all genders, racial and ethnic backgrounds, and ages. 

The more people join a clinical trial, the more we learn about how a drug, device, or procedure works across different types of patients. That means better, safer treatments for everyone.