cancer treatment centers of america? a legitimate place?

Has anyone ever heard of Cancer Treatment Centers of America? I saw commercials for it where they say they give hope to cancer patients whose doctors told them their cancer is incurable. For those of you that have heard of it or have been there, if several legitimate doctors have told a patient their cancer is untreatable, how are they going to cure the cancer? Are the doctors there licensed physicians? Are they simply trying to get rich of off a patients' desperation?