Cancer chemoprevention - Part 2: Hormones, nonclassic antioxidant natural agents, NSAIDs, and other agents

This two-part series provides an up-to-date summary of the various chemopre ventive agents currently in development and testing. Part I, published in l ast month's issue, focused on the retinoids, such as all-trans-retinoic aci d (A TRA [Vesanoid]), 9-cis-retinoic acid(9cRA) and isotretinoin (Accutane) and the carotenoids, such as beta-carotene and lycopene, and other "classi c" antioxidants, such as vitamins E and C and selenium. This second part ce nters ora hormonally mediated chemopreventives, such as tamoxifen (Nolvadex ), finasteride (Proscar), oral contraceptives, and dehydroepiandrosterone ( DHEA). A number of these agents have site-specific mechanisms of action and will be discussed as such. Also discussed in part 2 are various nonclassic antioxidant natural agents, including cat calcium, the polyphenols, the is othiocyanates, and genistein; nonsteroidal antiinflammatory drugs (NSAIDS) such as aspirin and sulindac; difluoro-methylornithine (DFMO [Eflornithine] ); oltipraz; and N-acetylcysteine.