All About Clinical Trials


Cancer research involves very highly trained doctors and scientists trying to figure out how cancer works. Research is always done by a set of rules, called the scientific method, that ensures the information will be valid. Researchers begin by looking for answers to questions like these:

  • What causes cancer?
  • What makes cancer cells keep growing?
  • What destroys cancer cells?
  • What stops cancer cells from growing?

By studying how cancer cells behave in animals, researchers can develop theories, or ideas, about potential treatments for humans with cancer. Once a treatment is ready to be tested on humans, researchers conduct clinical trials.

What are clinical trials?

A clinical trial is a medical research study that tests new ways to prevent, screen, diagnose, or treat a disease. The word “clinical” means related to examining and treating patients.

Cancer clinical trials help to determine if a treatment, drug, or procedure shows a better way of treating a particular cancer, or provides a way to treat a condition for which there wasn’t a treatment before.

It takes years of thought and planning to have a clinical trial accepted by the U.S. Food and Drug Administration (FDA). The FDA must approve the trial before researchers can recruit patients. Clinical trials allow patients access to the latest research treatments before they are available to the public.

Who sponsors clinical trials?

Medical or research institutions, pharmaceutical and biotechnology companies, the government, and nonprofit groups who want to improve current cancer treatment can all sponsor clinical trials Some trials are "investigator initiated," which means a researcher or doctor created the trial, but these trials face the same strict requirements.

What do the phases of clinical trials mean?

Phase I trials answer the questions: Is the drug or treatment safe? What is a safe dose? What are the side effects? Phase I trials are small, each only involving 20-80 participants.  These trials are  usually the first time a drug or treatment has been tested in humans.

Phase II trials tell researchers if the drug or treatment is effective in a larger group (100-300 participants) and help identify safety concerns.

Phase III trials determine within a large group (1,000 – 3,000 participants) if the experimental drug or treatment works better than what is currently used and if there are additional side effects. Most Phase III trials are randomized, meaning some participants will receive the experimental drug or treatment while others will receive the standard drug or treatment currently accepted by the medical community as best for their cancer type (standard of care).

Phase IV trials allow researchers to learn more about the drug or treatment and its risks, benefits, and best use.

Usually FDA approval comes after large phase III trials. However, sometimes special consideration is given to treatments that show great promise in early trials.

After enough data is gathered to prove that the new treatment is effective or more effective than current treatments, the FDA will investigate the findings and approve the treatment for use. After FDA approval, doctors can prescribe treatments to their patients without enrolling patients in clinical trials.

For a participant, what happens in a clinical trial?

Each clinical trial recruits and screens participants through participating treatment centers. In order to learn if a drug is effective, the participants must be similar in the type of diagnosis and other factors. Trials are designed to be very specific so researchers can know that the drug or treatment being studied is causing changes. For example, a clinical trial may be designed to answer a specific question, such as this: “Is this treatment effective for BRCA positive breast cancer in patients who have not received previous treatment?”

Participants must be eligible in order to qualify for the trial. Some possible requirements for eligibility include:

  • Cancer type
  • Stage
  • Specific tumor types or genetic markers
  • Treatment history
  • Age
  • Other medical conditions

If you qualify for a trial, your healthcare team will provide you will all the information about the trial. They will tell you, in a process called informed consent, how the trial will be conducted and the possible risks and benefits of the trial. You will then sign a document stating that you understand the details of the trial and that you are willing to participate. Even after signing the document of informed consent, you may withdraw from the trial at any time for any reason.

The way you receive treatment depends on the specific clinical trial. Clinical trial treatments can come in many forms. These include but are not limited to the following:

  • Intravenous (IV) medications  given  through a port or IV line
  • Shots
  • Oral medications
  • Surgery
  • Radiation

As with any cancer treatment, clinical trial treatments may come with side effects. Your healthcare team will help you manage these side effects. It is very important to report to your healthcare team any side effects that you experience. Part of what researchers are studying is how the treatment affects the whole body, not just the cancer cells.

To learn more about managing side effects, visit Nutrition Tips for Managing Side Effects.

How is a clinical trial treatment different from other treatments?

Patients who decide to participate in clinical trials receive excellent care and attention. Throughout the trial, your healthcare team will closely monitor you for improvements and adverse side effects.

Researchers want to control as much about your care as they can to make sure it is the treatment that is helping your cancer improve, and not something else. Because of this, you may have restrictions on what you can eat and what other medicines you can take.

Although you should always follow your treatment plan and not miss appointments, doing so is especially important with a clinical trial. Clinical trials must have consistency among the participants to know if the treatment really is working.

Are clinical trials a “last resort” for cancer patients?

Patients who are no longer helped by existing standard of care treatments may find that a clinical trial provides hope, but many patients begin their treatment program with a clinical trial because the treatment best suited to their situation is still being tested. Some clinical trials even exclude patients who have already received another form of treatment.

When participating in a clinical trial that evaluates if a new treatment is better than the current standard treatment for your cancer type, you will always receive treatment – either the standard of care or the new treatment being studied. By being in a clinical trial, you may receive the added benefits of a new treatment before it is  available to the public.

In many cases, cancer research moves at a faster pace than the FDA treatment approval process. Researchers have made important discoveries about biomarkers and mutations that affect how cancers respond to treatment. Because of the long time it takes for a treatment to be tested through the clinical trials process, many of these breakthrough treatments are still only available through participating in a clinical trial.

Related Resources

Why Should I Know About Clinical Trials?

Next Steps: How To Talk To Your Doctor About the Latest Research

Why Should I Consider a Clinical Trial?