Colorectal carcinoma and folate.

More than a million people a year worldwide develops colorectal cancer (CRC), with a mortality rate close to 33%. Most of the CRC cases are sporadic, only 25% of the patients have a family history of the disease, and major genes causing syndromes predisposing to CRC only account for 5-6% of the total cases. The following subtypes can be recognized: MIN (microsatellite instability), CIN (chromosomal instability), and CIMP (CpG island methylator phenotype). CRC arises from an accumulation of genetic and epigenetic alterations such as DNA methylation, which is able to modulate gene expression. Several studies in the literature show a possible correlation between an altered methylation in the promoter of tumor suppressor genes, proto-oncogenes, genes involved in DNA repair and the CRC risk; it has also been observed a global DNA hypomethylation, especially in the presence of a low folate uptake. Epigenetic changes are reversible, then could be interesting to evaluate on their relationship with dietary factors (as well as folates) and the genetic background of the individuals, for the development of novel strategies for cancer prevention.