Validated biomarker responses influence medical surveillance of individuals exposed to genotoxic agents.

There is currently a vast armamentarium of biomarkers for evaluating human exposures to environmental carcinogens, the effects of such exposures and/or susceptibility to disease outcome. Before application, however, these biomarkers require validation in terms of truly reflecting what is claimed. Transitional epidemiological studies bridge the gap between laboratory and field. In a transitional study, a biomarker response is the dependent variable being evaluated, while the intended measure, i.e. exposure effect or susceptibility, is the independent variable. Once validated, biomarker responses provide valuable data for use in making human health risk assessments and as guides for individual medical surveillance programmes. An analysis of medical decision-making illustrates how biomarker responses that increase the relative risk of subsequent disease occurrence change the 'pre-test likelihood' of having the disease, thereby influencing interpretation of medical diagnostic tests and even the choice of tests to be performed. This argues that an individual's response using salidated biomarkers should be made part of the medical record.