Why are there clinical trials?

Clinical trials are an essential process for the development of new medicines or treatment and to evaluate how people respond to them. For studies specific to cancer, the studies are performed with cancer patients to find out whether promising approaches to cancer prevention, diagnosis, and treatment are safe, effective and better than currently available treatments. With new drugs, extensive clinical trials are required by government health regulatory authorities before the drug is available to the public. Usually if the trial drug does not show any benefits over the current treatment then the drug does not get registered and is not available for use.