Biomarkers in Cancer Epidemiology

Since the term "molecular epidemiology" was proposed in 1982, molecular techniques have dominated biomarker research and have found an important and growing role in epidemiological studies. In several instances, the application of a molecular approach has represented an important step beyond the evidence brought by traditional epidemiological methods. Assessment of exposure to aflatoxins, enhanced sensitivity, and specificity of assessment of past viral infection, detection of protein, and DNA adducts in workers exposed to reactive chemicals such as ethylene oxide, are among the examples in which molecular epidemiology has contributed to the understanding of human cancer. If biomarkers are to offer new opportunities to overcome some of the limitations of epidemiology, then their added value over traditional approaches should be systematically assessed. Biomarkers should be validated and consideration of sources of bias and confounding should be no less stringent than in other types of epidemiological studies.