Primary prevention of cancer. The case for comprehensive school health education. Comprehensive school health education plays an important role in the primary prevention of cancer because so many of the health habits relating to cancer and other diseases have their onset early in life. A comprehensive health education program should begin early in life. Such education must be multifactorial from kindergarten through high school, should involve annual health screening, must be assessed annually, and is most effective when coordinated by a full-time health education teacher. Those concerned about the many problems of health behavior in our society should insist that such programs become mandatory in every state in this nation. 