The science and art of molecular epidemiology

This paper details some of the issues surrounding the growing field of molecular epidemiology Epidemiology is both a science and an art. The science of epidemiology entails applying classic epidemiological methods to understanding the distribution of diseases in populations. The art of epidemiology is interpreting the findings. Molecular epidemiology provides new opportunities for epidemiologists and other medical researchers to understand diseases and make public health recommendations for disease prevention and treatment. The value of molecular epidemiological studies, in terms of providing information that can be used to improve the health of populations, depends on how well both the science and the art are applied. Molecular epidemiology, an area of epidemiology that is somewhat ambiguous, encompasses utilisation of biomarkers and genetics as tools to define both exposures (factors that are inherited) and outcomes (factors that are acquired). As noted by Porta and colleagues,1 there are an increasing number of published articles with molecular epidemiology as a key word. Molecular epidemiology has been applied to many diseases, although a large percentage of published studies have focused on cancer. Within the cancer arena, most molecular epidemiological studies involving genetics have examined inherited genetic variants or polymorphisms. These genetic variants are exposures, a host characteristic, that may independently or through combination with other diet, lifestyle, or environmental exposures change disease risk. While the hope was that these studies would explain some of the inconsistent diet and lifestyle associations reported in the literature, many have added their own element of confusion.2–8 Evaluation of acquired tumour mutations as a disease end point with diet, lifestyle, and environmental exposure data can provide information about specific disease pathways. The central issue in the review by Porta and colleagues1 was classification of genetic mutations in tumours and appropriate inferences from this classification. Despite the growing …