Glossary of Terms
Some of the terms used throughout the Research and Clinical Trials site are defined below. For additional information, visit the National Cancer Institutes' Dictionary of Cancer Terms.
Adjuvant therapy: Treatment given after the primary treatment to increase the chances of a cure. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy or biological therapy.
Blinded study: A type of study in which the patients (single blinded) or the patients and their doctors (double blinded) do not know which drug or treatment is being given. The opposite of a blinded study is an open label study.
Clinical trial: Clinical trials are research studies in which people help doctors find ways to improve health and cancer care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose or treat cancer. The four different types of cancer trials include treatment, prevention, screening and quality of life trials.
Hematologic cancer: A cancer of the blood or bone marrow, such as leukemia or lymphoma.
Investigator: A researcher in a clinical trial or clinical study.
Phases of clinical trials: Most clinical research that involves the testing of a new drug progresses in an orderly series of steps called phases. This allows researchers to ask and answer questions in a way that results in reliable information about the drug and protects the patients. Clinical trials are usually classified into one of three phases:
- Phase I: These first studies in people evaluate how a new drug should be given (by mouth, injected into the blood 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.
- Phase II: A phase II trial continues to test the safety of the drug, and begins to evaluate how well the new drug works. Phase II studies usually focus on a particular type of cancer.
- Phase III: These studies test a new drug, a new combination of drugs or a new surgical procedure in comparison to the current standard. A participant will usually be assigned to the standard group or the new group at random (called randomization). Phase III trials often enroll large numbers of people and may be conducted at many doctors' offices, clinics and cancer centers nationwide.
Placebo: An inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo.
Prevention trials: These trials test new treatments (like a new cancer drug, new approaches to surgery or radiation therapy, new combinations of treatments or new methods such as gene therapy).
Protocol: An action plan for a clinical trials. The plan states what the study will do, how and why. It explains how many people will be in it, who is eligible to participate, what study agents or other interventions they will be given, what tests they will receive and how often and what information will be gathered.
Quality of life trials: These trials(also called supportive care trials) explore ways to improve comfort and quality of life for cancer patients.
Randomized clinical trial: A study in which the participants are assigned by chance to separate groups that compare different treatments; neither the researchers nor the participants can choose which group. Using chance to assign people to groups means that the groups will be similar and that the treatments they receive can be compared objectively. At the time of the trial, it is not known which treatment is best. It is the patient's choice to be in a randomized trial.
Regimen: A treatment plan that specifies the dosage, the schedule and the duration of the treatment.
Screening trials: Test the best way to find cancer, especially in its early stages.
Treatment trials: These trials test new treatments (like a new cancer drug, new approaches to surgery or radiation therapy, new combinations of treatments or new methods such as gene therapy).