Biomarkers in colorectal cancer.

Systemic therapies available for treatment of colorectal cancer have increased in recent years, leading to improved clinical outcomes. However, a significant proportion of patients fail to derive meaningful benefits, whereas others suffer from unacceptable toxicities. Therefore, not only does the search for novel and effective anticancer agents continue, there is also a pressing need to optimise the use of all treatments in the therapeutic armamentarium. In addition to knowledge gleaned from well-designed and relevant clinical trials, increasing effort is being invested into biomarkers. The identification and implementation of validated biomarkers has the potential to further our understanding of the biology of colorectal cancer and also to greatly improve the efficiency with which cancer treatments are administered.