What happens in phase II and phase III cancer prevention clinical trials?
• A phase II cancer prevention trial focuses on learning whether the agent being studied (medicine, vitamin, mineral, food supplement, or a combination of these) has an effect on preventing a particular type of cancer. It may also involve the use of cancer screening tests or evaluation of a method to better detect a cancer. • A phase III cancer prevention trial compares promising new agents with a standard agent or a placebo (an inactive substance that looks the same as, and is administered in the same way as, a drug in a clinical trial). Some phase III trials evaluate cancer screening tests to see if they can decrease the cancer death rate. • What happens in phase II and phase III cancer treatment clinical trials? • A phase II cancer treatment trial usually focuses on a particular type of cancer and provides preliminary information on the anticancer effect of a new drug or therapy. • A phase III cancer treatment trial compares a new treatment (or new use of a standard one) with the cu
