Molecular Markers for Colorectal Cancer.

Colorectal cancers develop through at least 3 major pathways, including chromosomal instability, mismatch repair, and methylator phenotype. These pathways can coexist in a single individual and occur in both sporadic and inherited colorectal cancers. In spite of the unique molecular and genetic signatures of colorectal cancers, nonspecific chemotherapy based on the antineoplastic effects of 5-fluorouracil is the cornerstone of therapy for stage III and some stage II disease. Techniques to recognize colorectal cancer at the molecular level have facilitated development of new signature drugs designed to inhibit the unique pathways of colorectal cancer growth and immunity.