The Role of Predictive Molecular Biomarkers for the Treatment of Metastatic Colorectal Cancer

Colorectal cancer (CRC) is a major public health problem in the USA and globally. Over the past 20 years, significant advances have been made in the treatment of patients with metastatic colorectal cancer (mCRC). Recent efforts have focused on developing molecular biomarkers to further define the subset of patients with mCRC who would derive a substantial benefit from anti-epidermal growth factor receptor (EGFR) therapy. Activating mutations in KRAS and NRAS are a predictive marker for resistance to anti-EGFR therapy in mCRC. BRAF^V600E and PIK3CA mutations have been reported as negative predictive markers for anti-EGFR therapy in mCRC. Microsatellite instability and immunologic biomarkers may be predictive markers for immunotherapy, including immune-checkpoint inhibitors in the near future. Next-generation sequencing technology is a powerful new tool for the discovery of predictive molecular biomarkers and to facilitate the delivery of personalized medicine. Herein, we review the current status of predictive molecular biomarker research in the treatment of mCRC.