Environment would appear to contribute substantially to prostate cancer etiology only when considered in its broadest sense as there is little evidence that environmental "chemical" exposures no matter what the source play an important role in prostate cancer development. However, in a broader sense, there is growing evidence that multiple components of diet may alter risk (including high fat, low fiber, low selenium, low vitamin D, high calcium, low lycopene, low vitamin E, low "phytoestrogens"). Our emphasis in the past two years however, has been on possible genetic pathways pertaining especially to androgen and vitamin D metabolism. We have published a series of papers showing how specific polymorphic markers in several genes in these pathways relate to prostate cancer risk and how these might help explain one of the primary features of prostate cancer epidemiology, the racial-ethnic variation in risk. As noted above, we summarized our work in this area with a detailed Perspectives in Cancer Research article in the journal Cancer Research. We are in the process now of further defining the role of diet (focused around the hypotheses of greatest current interest, as listed above), and the risk modifying effects of specific dietary factors on the genetic markers of risk.