New phases of clinical trials build and depend on information from earlier phases. A treatment showing activity against cancer in a Phase II trial will become part of a Phase III trial. Large numbers of patients are needed for Phase III trials, sometimes thousands of patients. Frequently, patients in these trials are randomized, or assigned by chance, to one of the treatments being studied. The other group receives the newer therapy and comparisons of results are studied.
Every clinical trial is designed to answer a set of research questions.
If you fit the guidelines for a trial, you may be eligible to take part. Each study enrolls patients with certain types and stages of cancer and certain health status. You would most likely be referred to a trial by your own doctor or by a doctor who knows your case. Some patients find out about trials from other sources such as medical publications, other pc survivors or resources such as the internet. In any case, you must have a reasonable understanding of your role in a research study and be freely willing to take part in it.