ABSTRACT
Cancer chemoprevention involves the use of naturally occurring or synthetic compounds that can be taken by healthy individuals to lower the risk of cancer developing which may be particularly useful in those with a naturally higher risk, such as those with an inherited cancer syndrome or a family history of cancer, or in those who have already had cancer to reduce the risk of recurrence. The chapter begins with an overview of cancer chemoprevention, and then describes in detail the various possible mechanisms of action of chemopreventive agents (e.g., effect on the metabolism or transport of carcinogens, inflammation and epigenetic processes, estrogen and androgen levels, and glucose metabolism, etc.). This is followed by a discussion of the challenges associated with evaluating potential chemopreventive agents (e.g., factors such as variation in contents of plant extracts, synergistic effects of constituents, the limitations of retrospective human studies and clinical trials, and the lack of suitable in vitro and in vivo assays). Next the various subfamilies of chemopreventive agents are described in detail, including both naturally occurring (e.g., flavonoids, chalcones, xanthones, phytoestrogens, alkaloids, glucosinolates, terpenoids, curcumin, organosulfur compounds, phenolic acids, and antioxidants) and synthetic compounds (e.g., aspirin, the nonsteroidal anti-inflammatory drugs, metabolic agents, and statins). Chemical structures and possible mechanism of action (when known) are provided for compounds in each subfamily. Finally, a brief conclusion is presented that outlines the future potential for chemoprevention in oncology.
