title: A framework for how environment contributes to cancer risk.
abstract: Evolutionary theory explains why metazoan species are largely protected against the negative fitness effects of cancers. Nevertheless, cancer is often observed at high incidence across a range of species. Although there are many challenges to quantifying cancer epidemiology and assessing its causes, we claim that most modern-day cancer in animals - and humans in particular - are due to environments deviating from central tendencies of distributions that have prevailed during cancer resistance evolution. Such novel environmental conditions may be natural and/or of anthropogenic origin, and may interface with cancer risk in numerous ways, broadly classifiable as those: increasing organism body size and/or life span, disrupting processes within the organism, and affecting germline. We argue that anthropogenic influences, in particular, explain much of the present-day cancer risk across life, including in humans. Based on a literature survey of animal species and a parameterised mathematical model for humans, we suggest that combined risks of all cancers in a population beyond c. 5% can be explained to some extent by the influence of novel environments. Our framework provides a basis for understanding how natural environmental variation and human activity impact cancer risk, with potential implications for species ecology.
authors.affiliation: Intstitut des Sciences de l'Evolution de Montpellier, Université de Montpellier, Place E. Bataillon, CC065, 34095, Montpellier Cedex 5, France.|Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM, 87501, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hochberg
authors.affiliation: Intstitut des Sciences de l'Evolution de Montpellier, Université de Montpellier, Place E. Bataillon, CC065, 34095, Montpellier Cedex 5, France.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Noble
mesh_terms: D000818:Animals; D004777:Environment; D006802:Human Activities; D006801:Humans; D009369:Neoplasms / Q000453:epidemiology* / Q000209:etiology; D012307:Risk Factors
keywords: Ageing; anthropogenic impact; body size; cancer risk; environment; epidemiology; evolutionary mismatch; global change; longevity; modern lifestyles; mutagens; pathogens