Harnessing epigenetics: Genome-wide DNA methylation assay for colorectal cancer therapy

Despite dramatic advances in cancer genomic medicine over the past decade, the complex and diverse nature of cancer makes it difficult to identify biomarkers for predicting treatment and prognosis in personalized medicine. The epigenome is a universal system that regulates genomic information and its expression and is involved in the development and progression of cancer. DNA methylation is a key epigenetic modification in cancer, leading to the inactivation of tumor suppressors and the activation of oncogenes through aberrant gene expression patterns. Therefore, epigenomic information may contain robust cancer biomarkers, suggesting that the development of epigenetic diagnostics will enable accurate disease stratification, prediction of treatment response and prognosis. However, in managing advanced colorectal cancer, as in other cancers, gene mutations and the expression of their products, but not epigenomic information, have been used to guide treatment or predict prognosis. This review explores the significance of DNA methylation in advanced colorectal cancer, focusing on its role in carcinogenesis and as a biomarker for predicting the efficacy of anti-EGFR antibody and prognosis. It also reviews the clinical application of recently developed genome-wide DNA methylation diagnostics and predicts the future of epigenomic diagnostics in cancer treatment.