Cancer risk is modulated by complex interactions between genetic, metabolic, and environmental (including lifestyle) factors throughout life. However, the understanding of the role of metabolic and environmental exposures is still limited and fragmentary. The concept of the exposome, defined as all exposures to which an individual is subjected from conception until death, is of central interest for research on the etiology and prevention of cancers. This paradigm has been translated into molecular terms, and an “internal exposome” has been defined as the complement of all biologically active chemicals in the body. This internal exposome is extremely complex and is made up of thousands of endogenous metabolites (the metabolome) and of thousands of xenobiotics derived from the digestion of the diet and from exposure to contaminants, pollutants, or drugs. The composition of the internal exposome varies widely according to individual lifestyle and environmental exposures.
Modern analytical technologies are implemented to measure this internal exposome in blood, urine, or tissue samples and to study its variations according to lifestyle and anthropometric parameters. The Biomarkers Group applies these technologies to measure the exposome in large epidemiological studies and human intervention studies to improve the understanding of the role of metabolic and environmental factors in cancer etiology. Novel biomarkers of metabolic and environmental exposures for cancer risk factors are identified through metabolomic approaches. Associations between these biomarkers and cancer are systematically explored to identify new cancer risk factors and shed new light on the mechanisms linking risk factors to cancer outcomes.