The impact of DNA testing on management of patients with colorectal cancer

Knowledge of the genetic basis of colorectal cancer has evolved over the past decades, allowing for the pre‐symptomatic identification of affected patients in those with familial syndromes and to the understanding of the multi‐step progression to carcinogenesis in tumors. Knowledge of the genes and pathways involved in colorectal cancer has allowed for targeted therapies in patients in addition to standard chemotherapy for those with metastases. Next‐generation sequencing technologies have now also allowed for the sensitive detection of circulating mutations derived from tumors, which can give insight into the presence of residual disease and has implications for changing the standard paradigms for treatment. This article will specifically review advances in targeted therapy in metastatic colon cancer and the progress being made in using circulating tumor DNA in patient management. Recognition of genes and pathways involved in colorectal carcinogenesis has led to the development of targeted therapies to improve outcomes in patients with metastases and next generation sequencing technologies to sensitively detect circulating mutations derived from tumors. The focus of this article will be to review advances made in targeted therapy and using circulating tumor DNA for managing patients with colorectal cancer.