Do we make optimal use of the potential of cancer prevention?

Three decades of intensive experimental and clinical research on cancer prevention have yielded an impressive body of scientific knowledge about cancer epidemiology, causation, and preventative measures. Despite our increased understanding in these critical areas, this knowledge is not being translated adequately into initiatives that will impact public health. The recent release of the World Cancer Research Fund/American Institute for Cancer Research report on diet and lifestyle strategies for cancer prevention--grounded in an evidence-based, systematic review of the published literature--is a strong acknowledgment of the benefits of a lifestyle approach to reduce cancer risk. The report also emphasizes the need to increase basic nutritional science research to make optimal use of the knowledge gained in the past three decades. Medical approaches--represented by chemoprevention clinical trials--also have become more focused based on results from basic science leads. The expansion of preclinical chemoprevention studies and greater attention to "first-in-human" prevention trials that safely shorten the timeline for new drug development are needed. The development of a prevention focus for what the U.S. Food and Drug Administration calls "exploratory investigational new drug studies" and what investigators at the National Cancer Institute are calling "phase 0" clinical trials will contribute to the decision-making involved in designing larger cancer prevention clinical trials. Past achievements in phase III prevention clinical trials--such as the Prostate Cancer Prevention Trial, the Breast Cancer Prevention Trial, and the Study of Tamoxifen and Raloxifene--have provided early successes as evidence of the potential for public benefit to be derived from this research. Nevertheless, the application of these findings to clinical practice and the design of future prevention trials remains a challenge. Current strategies include the refinement of risk assessment models for several major cancers. Additional initiatives, based on emerging basic and clinical research, involve the development of potential biomarkers for cancer risk and early detection by the National Cancer Institute's Early Detection Research Network. Although a recent progress report indicates that biomarkers of cancer susceptibility and exposure have been identified, continued work is needed to validate such markers for clinical use. Using this information optimally for prevention through lifestyle changes or medical interventions will demand commitments from public and private research institutions. Another area of emerging research is the development of a systems biology approach to cancer prevention. This will demand the creation of multidisciplinary teams of researchers from biological sciences, informatics and engineering scientists, and researchers from many fields not generally focused on disease prevention. To facilitate this and other new approaches, and to make effective use of information and strategies for cancer prevention, intensive training efforts must be implemented to develop the next generation of basic and clinical scientists--and physician researchers--capable of working in a cross- and multidisciplinary research environment. Training current researchers in new approaches will add efficiency to their combined research experiences.