Molecular Epidemiology of Cancer and the Use of Biomarkers

Abstract

Abstract Molecular epidemiology was introduced in the study of cancer in the early 1980s, with the expectation that it would help overcome some of the limitations of other forms of epidemiology. The expectation was that improvements in exposure assessment, the measurements of early and common changes preluding the disease, and the identification of subgroups in the population with higher (genetic) susceptibility to cancer might increase the ability of epidemiological studies to identify the causes of cancer and to investigate mechanisms. Research in molecular epidemiology in the last 20 years has, in fact, followed this general model and many key research findings are supportive. For example, as originally proposed for genotoxic carcinogens, a continuum between exposure and disease has been described, which involves metabolism (activation or deactivation of the carcinogen), adduction to proteins or deoxyribonucleic acid (DNA) (i.e., formation of links by the active metabolite), structural DNA alterations like mutations or chromosome damage, and finally cancer onset. Genetic, nutritional, and clinical susceptibility are viewed as potentially important effect modifiers. The chapter discusses the main methodological problems encountered in investigations of molecular epidemiology.