[Target Therapy in Unresectable or Metastatic Colorectal Cancer].

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in Korea. Despite recent developments in the treatment of CRC, the median overall survival time in patients with metastatic CRC is less than 30 months. The biologic agents that target the epidermal growth factor receptor (EGFR) or vascular endothelial growth factor (VEGF) have proven clinical benefits in the treatment of patient with metastatic CRC. Anti-EGFR agents, including cetuximab and panitumumab, as well as anti-VEGF agents, including bevacizumab, aflibercept, ramucirumab, and regorafenib have been shown to extend survival in combination with cytotoxic chemotherapy. In particular, the addition of anti-EGFR agents has demonstrated significant efficacy in patients with the RAS wild-type metastatic CRC. In the future, building a personalized treatment strategy, according to the clinical characteristics and biologic features of patients with unresectable or metastatic CRC, will be necessary. In this review, we summarized the mechanisms of target therapy, the results of main clinical trials, and the guideline of clinical practice in patients with unresectable or metastatic CRC.