Clinical trials are studies of new or emerging treatments or diagnostic techniques conducted on people, including those with cancer. The drugs and procedures that are tested usually show promise, but have not yet been used in standard treatment.

Generally, a clinical trial is proposed after the treatment or technique has been tested in the laboratory and on animals. Human volunteers are recruited to participate in a series of clinical trial testing sessions known as phases. By their very nature, the expected outcome of a clinical trial is not known. For this reason, the decision to participate in a clinical trial is often a difficult one for patients, who may or may not receive a health benefit from the new treatment, diagnosis or medication.

Many individuals participate in clinical trials for cancer because standard treatment methods have been unsuccessful. Clinical trials offer people the opportunity to try an unproven therapy that may help their prognosis. While the vast majority of people complete these trials safely, there have been incidences where patients were harmed by a treatment. However, many patients find that the medication or procedure tested in a clinical trial is worth the risk for a possible better quality of life with cancer or even longer survival. In addition, the information gleaned from a clinical trial may help millions of patients for years to come.