Trends in clinical use of targeted therapy for gastrointestinal cancers

Targeted drugs therapies that block the molecular pathways involved in the development and progression of gastro-intestinal (GI) cancers have recently gained considerable attention. In addition to agents targeting vascular endothelial growth factor (VEGF), epidermal growth factor receptor, the multi-kinase inhibitor, and regorafenib have also become available for the treatment of metastatic colorectal cancer patients. Currently, trastuzumab, an antibody targeting human epidermal growth factor receptor-2 (HER-2), in combination with cytotoxic drugs is considered as the standard treatment for patients with HER-2 positive gastric cancer (GC). The effi cacy of ramucirumab, a human monoclonal antibody that inhibits VEGF from binding to its receptor in GC, has also been recently demonstrated. At present, a great number of novel targeted drugs are in pre-clinical or clinical studies. In this review, we summarize trends in the use of molecularly targeted drugs that have proven to be effective for treating GI cancers, with a focus on emerging strategies for personalized treatment.