The search for new treatments begins in the laboratory, where scientists first develop and test new ideas. If an approach seems promising, the next step may be testing a treatment in animals to see how it affects cancer in a living being and whether it has harmful effects. Of course, treatments that work well in the lab or in animals do not always work well in people. Studies are done with cancer patients to find out whether promising treatments are safe and effective. Clinical trials are important in two ways.
Clinical trials contribute to knowledge and progress against cancer.
If a new treatment proves effective in a study, it may become a new standard treatment that can help many patients. Many of today's most effective standard treatments are based on previous study results. Examples include treatments for breast, colon, rectal, and childhood cancers. Clinical trials may also answer important scientific questions and suggest future research directions. Because of progress made through clinical trials, many people treated for cancer are now living longer.