Biomarkers in Colorectal Cancer

Colorectal cancer is the third most common cancer worldwide, with 1.36 million people diagnosed in 2012. The prognosis of colorectal cancer is better with an earlier diagnosis. The outcome of colorectal cancer may also be improved by targeting pathways involved in colorectal cancer formation, such as anti-epidermal growth factor receptor (EGFR) therapy. An understanding of colorectal carcinogenesis is essential for the design of molecular targeting. Recent advances in the molecular subtypes of colorectal cancer, methylation of DNA in colorectal cancer, and micro-RNA biogenesis, and their involvement in colorectal cancer have resulted in the identification of many new colorectal biomarkers. Such biomarkers may be used for earlier diagnosis of, selection of 'personalised' therapy for, and prognosis of colorectal cancer. Many of these biomarkers appear promising in small-scale studies. However, validation of their effectiveness with large-scale clinical trials is needed before routine clinical application. To this end, the recently established consensus molecular subtypes of colorectal cancer would enable like-for-like comparisons of the treatment outcomes of clinical trials.