Cancer immunoprevention--the next frontier.

Cancer immunotherapy is a rapidly developing field, but limited in its success by a high tumor burden and immune tolerance. In contrast, immunoprevention has the potential to prevent cancer before the development of immune tolerance, and to prevent cancer recurrence in the setting of minimal residual disease. Although immunoprevention for viral-induced cancers has been successful in the setting of hepatitis B and human papillomavirus vaccination, primary prevention of nonviral-induced cancers is in its infancy. In contrast, prevention of cancer recurrence after adjuvant treatment (secondary prevention) is gaining steam. This review provides an overview of the scope of research in cancer immunoprevention over the last three years and directions for future research.