Submitted to: CRC Press
Publication Type: Book / Chapter
Publication Acceptance Date: 7/14/2008
Publication Date: 11/24/2009
Citation: Ciappio, E., Mason, J.B. 2009. Folate and carcinogenesis-mechanisms. CRC Press. 2:235-263. Interpretive Summary:
Technical Abstract: A large and growing body of both pre-clinical and clinical studies pertaining to colorectal neoplasms constitutes the most compelling evidence for the protective effect of folate against the development of cancer, although evidence is also accruing in this regard for cancers of the breast, lung, pancreas, esophagus, and others. Complicating the matter are observations of a paradoxical nature: that overly abundant intake of folate may instead increase the risk of developing cancer if administered in an inopportune setting, such as to an individual who has existing foci of pre-cancerous or cancerous cells. In retrospect, what appears to be a paradoxical effect, however, is entirely consistent with our understanding of the cellular effects of folate. The likelihood of a 'dual effect' of folate is creating considerable consternation for those who translate scientific advances into public health policy since it exposes the fact that folate may have divergent effects on different segments of the population. Regardless of public health implications, however, any discussion purporting to explain the mechanistic avenues by which folate modulates the risk of carcinogenesis must take these disparate observations into account. The discussion that follows summarizes our present understanding of the cellular pathways by which the availability of folate and related nutrients modulate carcinogenesis.