Novel approaches to the prevention of colon cancer by nutritional manipulation and chemoprevention

Large bowel cancer is one of the most common human malignancies in Western countries including North America. This report details the preventive strat egies aimed at reducing the incidence and mortality of large bowel cancer b y nutritional manipulation and chemopreventive agents. During recent decade s, multidisciplinary research in epidemiology and laboratory animal model s tudies have contributed much to our understanding of the etiology of this c ancer; more importantly, it has enabled us to approach cancer prevention. A n impressive body of data thus far accumulated has provided important conce pts about dietary factors such as fat and fiber as key modulators of large bowel cancer. Compelling experimental evidence indicates that certain dieta ry lipids and fibers influence tumorigenesis in the colon. Data obtained in metabolic epidemiological and laboratory animal model studies are sufficie ntly convincing in showing the enhancement of colon cancer by certain types of fat and protection against it by certain dietary fibers. Our approach t o the primary prevention of large bowel cancer is to translate the findings from clinical epidemiological and laboratory studies into sound advice for patients and for the public at large to reduce fat intake and increase fib er intake, specifically cereals and grains. preclinical efficacy studies ha ve provided scientifically sound evidence as to how several phytochemicals and their synthetic analogues act to retard, block, or reverse carcinogenes is. Equally exciting are opportunities for effective chemoprevention with n onsteroidal anti-inflammatory agents, both synthetic and naturally occurrin g, or selective cyclooxygenase-2 inhibitors. Our exploration of the multist ep process of carcinogenesis has provided substantial insights into the mec hanisms by which chemopreventive agents modulate these events. Growing know ledge in this area has brought about an innovative combination of agents wi th different modes of action as a means of increasing efficacy and minimizi ng toxicity. There is growing optimism for the view that realization of pre ventive concepts in large bowel cancer will also serve as a model for preve nting malignancies such as cancer of the prostate and breast.