Molecular Mechanisms of Environmental Oncogenesis

Our understanding of the molecular bases of carcinogenesis has come a long way in the past 20 years, with consensus that nearly all cancers result from the accumulation of genetic abnormalities, largely influenced by environmental and lifestyle factors. As such, most cancer-causing genetic mutations are not inherited but rather emerge over the course of a person’s lifetime because of environmental exposures that are not yet fully understood. The field known as “environmental oncology” investigates the complex interplay between environmental factors and the vulnerability of living organisms to the transformative effects of carcinogenic substances. In fact, up to 60% of all cancers can be linked with environmental factors. This chapter discusses salient aspects of gene-environment-lifestyle interactions that define cancer outcomes including factors such as diet, tobacco use, alcohol, obesity, and physical activity, ultraviolet light, radon gas, pathogenic organisms, radiation, and pollution. The study of environmental oncology can help identify and reduce exposures to biological, chemical, physical agents linked to cancer outcomes with the goal of ultimately lowering the cancer burden by focusing “upstream” on controllable conditions and strategies for prevention rather than traditional “downstream” consequences.