Medicine: Arming Cancer's Natural Enemies

For decades the war against cancer has been waged with three often brutal weapons, the so-called cut, burn and poison methods of rooting out tumors: surgery, radiation and chemotherapy. But slowly, in laboratories and medical centers around the world, a fourth approach has been evolving. The idea: rallying the body's own immunological forces to destroy malignant cells. Last week scientists at the National Cancer Institute in Bethesda, Md., revealed some of the most promising results to date in the use of this new category called immunotherapy. In an unusual "special report," published in the New England Journal of Medicine, Dr. Steven...