What is a Clinical Trial?

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 patient's 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. ECOG is involved with various types of clinical trial protocols, including Phase I, II, and III protocols; intergroup cooperative studies; and drug company sponsored studies. Each phase of a clinical trial protocol attempts to answer questions that will enhance and improve cancer treatment and therapies.

Phase I

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.

Phase II

Once Phase I studies have been completed and a dosage level is known, Phase II studies can start. Phase II studies test the treatment in humans with various types of cancer to determine the effectiveness of the agent against a given tumor type. Additional information on side effects may also be gained.

Phase III

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 conducted by ECOG.

Informed consent

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 assured.

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