Chemotherapy and radiation failed to thwart Erika Hurwitz's rare cancer of white blood cells. So her doctors offered her another option, a drug for melanoma. The result was astonishing. Within four weeks, a red rash covering her body, so painful she had required a narcotic patch and the painkiller OxyContin, had vanished. Her cancer was undetectable. "It has been a miracle drug," said Mrs. Hurwitz, 78, of Westchester County. She is part of a new national effort to try to treat cancer based not on what organ it started in, but on what mutations drive its growth.
