Genetic and Epigenetic Biomarkers of Colorectal Cancer
Stephen A. Bustin and Jamie Murphy
from: Molecular Diagnostics: Current Research and Applications (Edited by: Jim Huggett and Justin O'Grady). Caister Academic Press, U.K. (2014)
Colorectal cancer (CRC) is one of the most prevalent cancers in the western world. Around 75% of primary CRC diagnoses are in patients with no apparent risk factor other than age, with the remaining 25% of patients having a family history of CRC that suggests a genetic contribution. Although some genetic alterations have been identified as the cause of inherited cancer risk in some families, they account for only around 6% of CRC cases. Hence additional, as yet undiscovered, genes and background genetic factors may drive the development of CRC. CRC arises and progresses through the acquisition of genetic and epigenetic alterations that drive the transformation from normal colon epithelium to adenocarcinoma. The clinical behaviour of cancer cells depends on complex and dynamic interactions between the effects of these alterations and the individual genetic and environmental host contexts. This results in significant variability in the response of individual patients to chemotherapy treatments that are not accurately predicted by conventional prognostic stratification and adjuvant therapy selection procedures. Consequently, there has been keen interest in the identification and functional characterisation of molecular biomarkers, with the expectation that they may facilitate accurate disease diagnosis, have prognostic potential for the individual, or predict patient-specific responses to chemotherapy. Undoubtedly, they will play a role in the future diagnosis and management of CRC; however, DNA-based biomarkers are currently not widely used by physicians and most potential markers are still in the discovery phase waiting to undergo clinical validation read more ...