This issue of the Proceedings of the Society for Experimental Biology and Medicine presents a forum that assesses the status of cancer prevention via 18 critical reviews of the elements that impact on carcinogenesis. Each article is written by a leading authority in the field of cancer prevention. Contributors were also selected with the goal of providing a broad-based view of the many facets of cancer prevention. We believe that, in addition to presenting the current state of knowledge in cancer prevention, the reviews also facilitate an appraisal of where current research in carcinogenesis is likely to lead in the coming years. Thus, we hope this issue of the Proceedings will prove to be a valuable reference for readers now and in the future, as the various ideas presented begin to unfold. The reviews emphasize that effective use of chemopreventive agents, whether naturally occurring or synthetic, will be realized only in the context of a fundamental understanding of the processes of carcinogenesis and tumorbiology. They also illustrate why success in preventing cancer will be enhanced by improved methods for identifying people at increased risk for different types of cancer. The importance of understanding and minimizing barriers that limit the inclusion of high-risk individuals in cancer prevention trials, while communicating our understanding of chemoprevention to those it is intended to benefit, is considered. The first section of this special issue of the Proceedings focuses on general perspectives for prevention of cancer. Mechanisms by which cancer canbe prevented, even when the exact causative factor(s) is unknown or cannot be removed from the environment, are reviewed, as are the use of epidemiologic methods to identify risk factors in specific types of cancer. Also discussed in Section I are the properties of intraepithelial neoplasia relevantto cancer prevention and the development of surrogate end points for clinical trials.