Except for cancer, U.S. adults most fear getting Alzheimer's disease, but few make preparations for the onset of the disease, a survey indicates. Although many fear Alzheimer's, 62 percent admit they know little or nothing about the disease. Forty-one percent say they fear cancer, 31 percent say they fear Alzheimer's disease, 8 percent fear heart disease, 8 percent fear stroke and 6 percent fear diabetes. The telephone survey of 1,007 U.S. adults was conducted in September. Nearly a quarter of all adults are extremely or very concerned that they may some day provide care for a loved one with Alzheimer's.