Advances in nutrition and cancer 2

This volume includes the contributions presented at the Second International Symposium on Nutrition and Cancer. During this Conference, experts from different disciplines faced pivotal and timely questions on the interactions between human nutrition and the development of malignancies. The major scientific advancements in the last six years derive from the extensive use of molecular approaches to perform research in the nutritional field. Moreover, the fundamental observation of R. Doll and R. Peto (1981), which suggested that at least 35% of all cancers (with large differences among different tumors) might be prevented by dietary regimens, has been definitively confirmed by epidemiological studies. However, the relationships between diet and cancer are quite intricate and complex; it is difficult, and, not methodologically correct, to reduce them to simple terms: metabolic and hormonal factors, contaminants and biological agents, and deficiency of specific protective nutrients are all components of the same puzzle. The molecular studies reported in this volume include all of the major aspects of investigation on human nutrition and malignant transformation. In the last decade a large number of compounds responsible for the biological activity of human foods have been identified and characterized. These molecules not only include important and well-known risk factors but, most promising, compounds, which might exert chemopreventive activity. Among them, antioxidants (such as vitamins, phenols, and lycopene) seem to play a critical role in reducing the risk of cancer at different anatomical sites, including colon, breast, and prostate malignancies. Other molecules, derived from fiber bacterial intestinal degradation (short fatty acids), are of interest, even if their importance has not been completely unravelled and is still the subject of debate. The relevance of the individual genetic background, as an independent risk factor also in the development of diet-related cancer, opens new perspectives for molecular epidemiology. The working hypothesis is that genetic differences in the metabolism of nutrients might result in a different incidence of malignancies. A further development in the genetic field is the understanding of mechanisms involved in the repair of DNA alterations. Also in this case, the occurrence of genetic polymorphisms might result in distinct responses to identical dietary risk factors. A further promising advancement relates to the finding that active dietary molecules might regulate cell transduction pathways and gene expression and, in turn, cell proliferation and differentiation. In recent years, the precise knowledge of the principal protein players of cell division cycle machinery has allowed the elucidation of the growth biochemistry. A number of recent data suggest that dietary-derived compounds, including radical scavengers, affect cell proliferation by acting on the cell division cycle engine and thus might control the process (and the rate) of malignant transformation. The above themes are described in this new volume, but the final word on their true importance must wait until the dust of the present time has settled. What we can anticipate is that the rapid development of new methodologies and the convergence of different types of approaches (molecular, epidemiological, intervention) to clarify the relationship between Nutrition and Cancer will require new appraisal, with continuous updating, on this central aspect of human health.