Cancers are caused by combined genetic and non-genetic changes induced by environmental
factors that trigger inappropriate activation or inactivation of specific genes leading to
neoplastic transformations, or abnormal cell growth. There is a lack of information about key
cellular events that occur in early stages of cancer development as well as environmental
factors and internal cues that trigger these changes.
Advances in molecular epidemiology are allowing researchers the possibility of
simultaneously identifying multiple changes affecting the genome and extra-genomic
environment of normal, precursor and cancer cells as well as their link to the environment. It
should be now possible to define which genetic and other alterations, or combinations
thereof, can be interpreted as reliable biomarkers of exposures. By identifying changes
associated with tumour cells and surrogate tissues associated with specific known and
suspected environmental risk factors, it may be possible to identify particularly high-risk
individuals and potentially design an efficient strategy for cancer prevention.