Abstract D090: Can exposure to environmental chemical and biologic agents increase the risk of prostate cancer and its outcomes?

Introduction: It is generally believed that the environment plays some role in the development of prostate cancer, but the extent of that role is not understood. The objective of this study is to perform a systematic review of the literature to bring together the best available evidence on the suspected relationship between the environment and prostate cancer. Methods: PubMed, Web of Science, CINAHL, CancerLit, and the Cochrane Library were searched. We examined peer-reviewed English language studies examining the association between the environment and prostate cancer risk between 1990 and May 31, 2019. We further included studies if they met all of the following criteria: (1) considered at least one chemical or biological agents; (2) reported risk for incidence, mortality, serious adverse events, or hospital admissions. We extracted data from each study, including location, health outcome, and risk estimates. Results of the studies were combined using a qualitative synthesis due to the variation across and within outcomes in reported results. Results: We assessed 198 studies, of which we selected 51 for an in-depth review. Thirty-four articles fulfilled our predetermined inclusion criteria and were included in the qualitative synthesis. Of the 34 articles, 16 were prospective cohort studies, and 9 were case-control studies. These 34 articles explored a number of environmental agents including chemicals, ionizing radiation, electromagnetic fields, and infectious agents. Chemical exposures included second-hand exposure to industrial chemicals and to environmental carcinogens. Several of the studies (n=21) were based on ecological comparisons and did not provide a quantitative risk estimate. Exposure to ionizing radiation and electromagnetic fields showed no association with risk of prostate cancer. There is an inconsequential link between pesticides and an increased risk of prostate cancer through a potential endocrine-disrupting mechanism based on androgen imbalance. In most cases the overall evidence was inadequate in number, reported outcomes, quality of study to establish a relationship between a specific environmental agent and risk of prostate cancer; the evidence from chemical exposure studies was not sufficient to draw an inference. Conclusions: Overall, the reviewed epidemiologic evidence provides a weak level of evidence supporting the hypothesis that there is a causal relationship between environmental exposures and increased risk of prostate cancer. Because a large number of individuals are exposed to suspected environmental carcinogens, investigation of the association between prostate cancer and environmental chemical and biological agents deserves to be a high priority. Such investigations do not only have health implications but can also provide a fundamental understanding of the process of prostate carcinogenesis.

Citation Format: Oluwabunmi Dada, Hadiza Galadima, John Cyrus, Georges Adunlin. Can exposure to environmental chemical and biologic agents increase the risk of prostate cancer and its outcomes? [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D090.