In cancer research, a clinical trial is a study designed to answer scientific questions. Advances in cancer treatment have occurred largely because of the knowledge gained in large clinical trials that test new and better ways to treat cancer patients. Some clinical trials test new treatments, investigate new ways of preventing cancer, screen patients for earlier diagnoses and monitor the quality of life and/or psychological impact of cancer, while others detect cancer in its earliest stages.

The search for good cancer treatments begins with carefully controlled laboratory research. The promising results of these experiments are then tested and monitored in patients with cancer to determine the effectiveness of the treatment. Clinical research is the bridge between the basic research laboratory and the patients bedside.

With any new treatment, there may be risks, as well as possible benefits. During a trial, as information is gained about a new treatment, there may be some unforseen negative side effects that occur. However, patient safety is the number-one priority in clinical trials, and patients are closely monitored. If a clinical trial shows that a new cancer treatment is better than the current standard treatment, the new treatment may become the standard for treating that particular kind of cancer.

Once drug development has been completed from initial laboratory studies, clinical trials progress through phases of testing. The trials are identified as Phases I, II, III and IV. Each phase of a clinical trial protocol attempts to answer questions that will enhance and improve cancer treatment and therapies.

Phase I studies test a particular treatment in humans after it has been studied in the laboratory. The purpose of Phase I studies is to determine the maximum tolerated dose or amount of the treatment and answer questions about the best way to give the new treatment. Phase I studies are carefully controlled by the NCI's Cancer Therapy Evaluation Program (CTEP). Phase I studies are carried out by knowledgeable investigators who meet certain criteria set by CTEP.

If the treatment is found to be effective, Phase III studies compare it to the standard treatment. This is done by having two or more "arms" of treatment in which patients are randomly selected to participate. The arm in which the patient participates is decided by chance (by a computer), not choice. This randomization assists in making the groups as equal as possible so that sound conclusions can be drawn from study results. Patients are randomized by a number of factors that may affect the outcome of the study (age, performance status, tumor grade, stage of disease, etc.). In all treatment arms, patients receive the best care available. The Data Monitoring Committee oversees all Phase III studies.

Every patient participating in a medical research study, by law in the United States, must sign an informed patient consent form that explains the research study, the foreseeable risks, benefits, other appropriate treatments and where to find further information. It also explains a patient's rights as a participant in the trial. If at anytime a participant is not comfortable with the trial, they have the right to withdraw. Also, confidentiality of patients' records is ensured.

People participate in cancer clinical trials for a variety of reasons. Volunteering for research studies can give patients access to promising new drugs long before they are available to the general public. Although there is always a chance that a new treatment will prove to be disappointing, there is reason to believe that it will be as good as, or better than, current treatments. Every effort is made to ensure the patients' safety; the care from the physicians during the course of the study is highly controlled and monitored. The patients who take part in clinical trials become part of a network of clinical trials carried out around the country. Included in this network are cancer experts who have pooled their experience to design and monitor the clinical trials. Patients in these studies receive the benefit of this specialization and expertise. Patients considering participating in clinical research should talk about it with their doctors and medical caregivers. They also should ask about the credentials and experience of the individuals and the facility involved in the study.

If you are interested in participating in a clinical trial, you should first talk to your doctor, who can help determine which trials would be best for you. Also, you can call the NCI's Information Hotline at 1-800-4-CANCER to find information on active studies in your disease site. Finally, you may want to contact one of the major cancer centers or university medical centers in your region, which can provide information about the studies in which they are currently participating, and can recommend a health care professional in the area who can help determine your eligibility.

• What is the main purpose of the trial?
• Who is sponsoring the trial?
• How long will the trial last?
• Where is the trial being conducted?
• What does the treatment involve?
• What tests or procedures will I have to undergo?
• How often will I need to come in, and where do I have to go?
• What risks are involved—short-term and long-term side effects?
• What happens if I am harmed by the trial?
• What are the possible benefits?
• How will the trial affect my daily activities?
• What other treatment options are available?
• Can I opt to remain on this treatment, even after termination of the trial?
• Are there any costs I will have to pay?
• How will I be notified of the results of the study?