Molecular epidemiology: cancer risk assessment using biomarkers for detecting early health effects in individuals exposed to occupational and environmental carcinogens.

Detecting changes that precede the overt symptoms of cancer and identifying measurable indices of such changes in persons exposed to occupational and environmental carcinogens constitutes one of the primary objectives of molecular epidemiology research. Biomarkers represent a valuable research tool that makes it possible to attain that objective. Suitably selected biomarker sets may provide information on the extent of exposure to carcinogenic agents (internal dose, biologically effective dose), detect early changes caused by those agents in the exposed organism, and identify individuals with a particularly high risk of cancer development. The tremendous progress in research on the mechanisms of cancer initiation and promotion has enabled the assessment of cancer risk in healthy individuals by examining specific results from determinations of suitably selected biomarkers. The finding that gene defects (gene mutations and changes of their expression) constitute the background of carcinogenesis has resulted in molecular biology becoming focused on detecting defective genes or proteins synthesized under control of the defective genes.