Role of epigenetic events in chemical carcinogenesis--a justification for incorporating epigenetic evaluations in cancer risk assessment.

Recent advances in field of cancer research have established that all major human cancers, in addition to having a large number of genetic alterations, exhibit prominent epigenetic abnormalities that can be used as biomarkers for the molecular diagnosis of cancer. Currently, epigenetic markers have shown promise in establishing the diagnosis and prognosis of all major human cancers. Additionally, accumulating evidence suggests that epigenetic alterations may be early indicators of genotoxic and non-genotoxic carcinogenic exposure and may be used as biomarkers in the assessment of the carcinogenic potential of environmental chemical and physical agents. This review presents current evidence on the role of epigenetic alterations in chemical carcinogenesis and highlights a number of advantages of epigenetic biomarkers over traditionally used methods in cancer risk assessment.