About UCSF Search UCSF UCSF Medical Center

About Clinical Trials

What Are Clinical Trials All About?

Research studies conducted with cancer patients are called clinical trials. As a cancer patient, you may take part in a clinical trial. This site will explain what clinical trials are, and help you make an informed decision about entering a trial.

It is a difficult and stressful time when someone is diagnosed with cancer. Treatment decisions are being made and it is often hard to understand or remember complex medical explanations. The information on our web page is meant to supplement what your doctors tell you. It provides answers to questions that are most often asked about clinical trials.

Here is a helpful link to a list of questions provided by the NCI, National Cancer Institute.

We hope this guide will help you understand how clinical studies are designed and carried out. Of course, whether or not you participate in a clinical trial, there are good standard treatments and excellent care available for cancer patients. If you decide not to take part in a trial you can still receive excellent medical care. The decision to enter a clinical trial is always up to you.


What Is a Clinical Trial?

In cancer research, a clinical trial is a scientific study conducted with volunteer cancer patients. These studies are performed in order to evaluate a new treatment and are designed to answer scientific questions to find new and better ways to help people with cancer. Patients who volunteer to participate in clinical trials often have the first chance to benefit from an effective new therapy. Clinical trials are available for patients with many types of cancers at different stages.

Discovering good cancer treatments begins with basic research in laboratory and animal studies. Before a new treatment is tried with human patients, it is carefully studied in the laboratory. Laboratory research points out the new methods most likely to succeed and, as much as possible, shows how to use them safely and effectively. But this early research cannot predict exactly how a new treatment will work with patients.

With any new treatment there may be risks as well as possible benefits. There may also be some risks that are not yet known. Clinical trials help us find out if a promising new treatment is safe and effective for patients. During a trial, more and more information is gained about a new treatment, its risks, and how well it may or may not work.

Only patients who volunteer to participate take part in a clinical trial. Your doctor or nurse may ask if you would like to enter a trial. You may hear about a trial from a fellow patient. Learn as much as you can about the trial, before you make up your mind.


Types of Clinical Trials

  • Treatment Trials
    Test new treatments (a new cancer drug, new approaches to surgery or radiation therapy, new combinations of treatments, or new methods such as gene therapy).
  • Prevention Trials
    Test new approaches (medicines, vitamins, minerals, or other supplements) that doctors believe may prevent cancer or lower the risk of a certain type of cancer.
  • Screening Trials
    Study the best way to test for and find cancer, especially in its early stages.
  • Quality of Life Trials or Supportive Care Trials
    Explore ways to improve the comfort and quality of life for cancer patients.

What Are the Phases of Clinical Trials?

Most clinical research that involves testing a potential new treatment progresses in an orderly sequence of steps, called phases. These are highly regulated activities that allow researchers to pose questions that result in reliable information about the drug and protect patients. For the most part, clinical trials are classified into one of three phases:

  • Phase I Trials
    These are the first studies done with people to evaluate how a new drug should be given (by mouth, injected into a vein, or injected into the muscle), how often, and what dose is safe. A phase I trial usually enrolls only a small number of patients, sometimes as few as a dozen. The research treatment has already been well tested in laboratory and animal studies but no one knows how human patients will react. It may involve significant risk for this reason.
  • Phase II Trials
    A phase II trial continues to test the safety of the drug, and begins to evaluate how well the new drug works against a particular kind of cancer.
  • Phase III Trials
    These studies test a new drug, a new combination of drugs, or a new surgical procedure compared to the current standard treatment. A participant will usually be assigned to the standard group or the new group at random. Phase III trials often enroll large numbers of people and may be conducted at many doctors' offices, clinics, and cancer centers nationwide.

Why Are Clinical Trials Important?

Clinical trials help us find new and better treatments. Advances in medicine and science are the results of discoveries made from research. Before a new treatment can be widely available, it must be proven to be safe and effective in scientific studies. To be valid, and depending on the type of study, it must include a certain number of patient volunteers. The treatments we use today were discovered to be effective in clinical trials.


Why Would I Be Interested in a Clinical Trial?

There are many reasons. Often it is hope. Hope for some benefit for yourself; hope for an effective treatment; a longer time to live, and a way to feel better. Just as often, patient volunteers want to contribute to a scientific research effort that may help others.

There is always a chance that a new treatment will be disappointing. However, the scientists and doctors involved in a study have reason to believe it will be as good as, or better than, current treatments. The volunteer patients in a clinical trial are among the first to receive new research treatments before they are more widely available. How a treatment will work for a patient in a trial can't be known ahead of time. Even standard treatments, although effective in many patients, do not carry sure benefits for everyone. You should choose if you want to take part in a study or not, only after you understand both the possible risks and benefits.

Patients participating in clinical trials are carefully monitored during the study as well as followed up afterwards. You become part of a network of clinical trials carried out around the country. In this network, doctors and researchers share ideas and experience to design and monitor clinical studies. Patients in these studies receive the benefit of their expertise.