ABSTRACT
This chapter reviews known and suspected prostate carcinogens and explores possible explanations for the enormous disparity in prostate cancer occurrence between humans and most other mammalian species. Tobacco smoke, which is a major cause of human cancer and contains many carcinogenic, co-carcinogenic, and tumor-promoting chemicals, has until recently never been found to be associated with prostate cancer risk. A slightly increased risk for prostate cancer has been found for farmers and farm workers in many, but not all, studies. A number of previously summarized reports suggest that exposure to ionizing radiation increases risk for prostate cancer in workers in the nuclear industry. Direct application of chemical carcinogens to prostate tissue in experimental animals can produce sarcomas or squamous cell carcinomas. It is remarkable that the enhancing effect of testosterone on prostate carcinogenesis is confined to the dorsolateral and anterior prostate and does not occur for the ventral prostate.
