A clinical trial is a research study designed to answer specific medical questions regarding cancer care.
The clinical trial is a scientific study that follows a written guideline (protocol) or recipe for treatment. It is the only scientific mechanism designed to test the effectiveness of new and promising therapies. The clinical trial provides intensive testing of new or updated treatment regimens. Almost all standard treatments in the field of oncology (cancer) originated from clinical trials. These trials are conducted by medical, surgical and radiation oncologists (cancer specialists).
Cancer clinical trials are the key to preventing, diagnosing and treating all types of cancer. It is estimated that 60% of all cancer patients in the United States are being cured. Yet, fewer than 3% of adult cancer patients participate in clinical trials. In contrast, about 71% of children enter clinical trials. This has led to major advancements in treatment and high cure rates for many childhood cancers such as Wilms' tumor (malignant neoplasm of the kidney), osteosarcoma (tumor of the bone), and childhood leukemia (cancer of the blood).
Types of clinical trials
Clinical trials that involve new drugs or devices for humans must first be tested in animals. When a new or investigational drug has been discovered that shows anti-tumor activity in laboratory animals, it is tested on a small number of patients with different types of cancer, usually in a university setting. These are called Phase I trials and are designed to test the maximum tolerated dose (MTD) and side effects or toxicities of a new drug. This phase also helps determine how a new drug should be given (by mouth or by injection). The patients being tested are those with advanced cancer who have exhausted other treatment options. These patients may not personally benefit from participation in the trial.
If the investigational agent or drug continues to show anti-tumor activity and if the side effects are tolerable and not life-threatening, the drug is moved into a Phase II trial for further testing. In a Phase II trial, the drug is offered to a specific group of patients having the same tumor type. The drug is being tested to determine if it regresses tumor growth. Additional information on side effects of the treatment is also evaluated in this phase.
If the drug continues to show response to the patient's cancer, it is moved into a Phase III trial. At this phase, the investigational treatment is compared to the standard cancer therapy. This is to ensure that no one in a study is left without any treatment when standard treatment is available. If there is no standard therapy, a placebo (a pill that looks like the drug being studied but contains no active medication) may be used for comparison. However, researchers must inform potential patients of this possibility before patients decide whether to participate. Patients are usually assigned their treatment by a process called randomization, which is similar to the toss of a coin. Comparison or randomized trials help
The objectives of Phase III trials include tumor response to treatment, survival, and quality of life during therapy. This phase can involve 400-1000 patients. Anti-tumor response by a significant proportion of the involved patients indicates that the investigational drug or treatment is ready to be submitted to the Food and Drug Administration (FDA) for approval. If approved, the drug is released from investigational status and made available for commercial use in patients with the specifically tested type of cancer.
What to expect as part of a clinical trial
Taking part in a clinical trial does not mean that patients are seen as or treated like "guinea pigs, " or that they will receive substandard care. Cancer patients who enroll in clinical trials may be the first to receive a new technique or drug that becomes the standard of care. Clinical trials, however, have risks, as well. The treatment or drug being tested is new, and the side effects may be unknown. The cancer patient, his or her loved ones, and the patient's physician must weigh the risks and benefits when deciding whether or not to enroll in a clinical trial.
When patients participate in a clinical trial, they receive treatment in a cancer center, hospital, clinic, and/or doctor's office. Doctors, nurses, social workers, and other health professionals may be part of the treatment team, and will closely monitor progress. Cancer clinical trial patients:
- are, as stated above, under close scrutiny
- are seen frequently by the members of the treatment team
- are tested often
- follow the treatment plan their doctor prescribes and as according to the study's protocol
- and may also have other responsibilities, such as keeping a log or filling out health forms.
Some studies continue to check on patients after their treatment is completed.
Klimaszewski, Angela D., Jennifer L. Aikin, Monica A. Bacon, Susan A. DiStasio, Heidi E. Ehrenberger, Bertie A. Ford, Ed. Manual for Clinical Trials Nursing. Pittsburgh: Oncology Nursing Press, Inc., 2000.
Murphy, Gerald P., Walter Lawrence, Jr., and Raymond E.Lenhard, Jr., Ed. American Cancer Society Textbook of Clinical Oncology. Atlanta: American Cancer Society, 1995.
Varricchio, Claudette, Ed. A Cancer Source Book for Nurses. Atlanta: Jones and Barlett Publishers, 1997: pp. 69-79.
National Cancer Institute. An Introduction to Clinical Trials. January 2000 National Cancer Institute. 8 July 2001. <http://cancertrials.nci.nih.gov>.
National Cancer Institute. Cancer Trials. 8 July 2001. <http://cancertrials.nci.nih.gov/>
Phyllis M. Stein, B.S., CCRP
—Cancer of the blood and bone marrow.
Maximum tolerated dose (MTD)
—The highest dose of an investigational drug that patients can tolerate without life-threatening or fatal side effects.
—The study of cancer.
—A tumor of the bone. The most common childhood cancer.
—A preparation without medication.
—A written, scientific guideline used for treatment planning in clinical trials.
—A malignant tumor of the kidney; occurs most frequently in children.
QUESTIONS TO ASK THE DOCTOR
- Am I eligible for a clinical trial?
- Where can I get more information?