Potential usefulness of DNA methylation as a risk marker for digestive cancer associated with inflammation.

DNA methylation has been deeply involved in the development and progression of digestive cancer, while aberrant DNA methylation has also often been observed in aged and inflammatory digestive tissues. Helicobacter pylori-related chronic gastritis, ulcerative colitis, and hepatitis B virus- and hepatitis C virus-related chronic hepatitis, are significant risk factors for developing cancer. A number of studies have revealed the specific methylation patterns for specific tissue types. DNA methylation status is stably transmitted to daughter cells. Also, unlike genetic mutations, it is possible to detect very tiny amounts of methylated DNA among tissues. Therefore, the use of aberrant methylation as a marker could be applicable to risk estimation of cancer development. We discuss the potential usefulness of DNA methylation as a risk marker for inflammation-associated digestive cancer, especially with attempts on gastric cancer, ulcerative colitis-associated cancer, and hepatitis B virus- and hepatitis C virus-related hepatocellular carcinoma.