Cancer clinical trials differ according to their primary purpose. They include the
These trials test the effectiveness of new treatments or new ways of using current
treatments in people who have cancer. The treatments tested may include new drugs
or new combinations of currently used drugs, new surgery or radiation therapy techniques,
and vaccines or other treatments that stimulate a person’s immune system to fight
cancer. Combinations of different treatment types may also be tested in these trials.
These trials test new interventions that may lower the risk of developing certain
types of cancer. Most cancer prevention trials involve healthy people who have not
had cancer; however, they often only include people who have a higher than average
risk of developing a specific type of cancer. Some cancer prevention trials involve
people who have had cancer in the past; these trials test interventions that may
help prevent the return (recurrence) of the original cancer or reduce the chance
of developing a new type of cancer
These trials test new ways of finding cancer early. When cancer is found early,
it may be easier to treat and there may be a better chance of long-term survival.
Cancer screening trials usually involve people who do not have any signs or symptoms
of cancer. However, participation in these trials is often limited to people who
have a higher than average risk of developing a certain type of cancer because they
have a family history of that type of cancer or they have a history of exposure
to cancer-causing substances (e.g., cigarette smoke).
These trials study new tests or procedures that may help identify, or diagnose,
cancer more accurately. Diagnostic trials usually involve people who have some signs
or symptoms of cancer.
Quality of life or supportive care
These trials focus on the comfort and quality of life of cancer patients and cancer
survivors. New ways to decrease the number or severity of side effects of cancer
or its treatment are often studied in these trials. How a specific type of cancer
or its treatment affects a person’s everyday life may also be studied.
Adapted from the National Cancer Institute's PDQ Database: http://www.cancer.gov/cancertopics/factsheet/Information/clinical-trials.
(Accessed December 2010)