Ames, B. N., Gold, L. S., and Willet, W. C. The causes and prevention of cancer. Istituto della Enciclopedia Italiana: Enciclopedia del Novecento, (in press, 1998).
Epidemiological evidence indicates several factors likely to have a major effect on reducing rates of cancer: reduction of smoking, increased consumption of fruits and vegetables, and control of infections. Other factors are avoidance of intense sun exposure, increases in physical activity, and reduction of alcohol consumption and possibly red meat. A substantial reduction in breast cancer is likely to require the modification of sex hormone levels, and the development of practical methods for doing so should be a high research priority. Resolution of the potential protective roles of specific antioxidants and other constituents of fruits and vegetables deserves major attention. Already, risks of many forms of cancer can be reduced and the potential for further reductions is great. Mechanistic studies of carcinogenesis have indicated an important role of endogenous oxidative damage to DNA that is balanced by elaborate defense and repair processes. The rate of cell division, which is influenced by hormones, growth, cytotoxicity, and inflammation is also key as this determines the probability of converting DNA lesions to mutations. These mechanisms are likely to underlie many epidemiologic observations, and together suggest practical interventions and areas for further research.
We discuss in this paper major and minor causes of cancer with an emphasis on mechanisms. The understanding of mechanisms is advancing rapidly. As causes and mechanisms become clear, prevention becomes possible. Henderson, Ross, and Pike reviewed the likely causes of cancer in l991 (Henderson et al., 1991) following by a decade the comprehensive review of Doll and Peto (1981). The Henderson et al. (1991) review complements ours and includes a table of the estimated numbers of cancers in the U.S. by site, with known and possible causes. Detection of early cancers and precursor lesions is important, but beyond the scope of this review.
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Last updated: April 16, 1998