Antioxidants as Chemopreventive Agents for Breast Cancer

In the last decade the simplistic, stepwise concept of initiation, promotion, and progression has matured to a better understanding of the genotypic changes that ultimately lead to cancer. The hypothesis has been proposed that it may be possible to intervene pharmacologically during this process and that carcinogenesis may be arrested or reversed by synthetic or naturally occurring agents. Evidence supports the potential role of antioxidant agents in cancer prevention. Basic research has demonstrated that antioxidants can trap organic free radicals and prevent tissue damage. Although observational epidemiologic studies are not entirely consistent, many show an inverse association between dietary intake or blood levels of antioxidants contained in foods and subsequent cancer risk. The Breast Cancer Prevention Trial (BCPI) recently concluded that the antioxidant drug tamoxifen (Nolvadex) which was being evaluated for its potential ability to prevent primary breast cancer among high-risk candidates reduces breast cancer risk by 45% among women younger than 50, Long term side effects have not been evaluated.