Challenges in molecular targeted therapy for gastric cancer: considerations for efficacy and safety.

INTRODUCTION: The Cancer Genome Atlas Research Network recently proposed a molecular classification for gastric cancer (GC) into four subtypes based on comprehensive evaluation. While the mechanisms of molecular targeted therapies in GC were confirmed by multiple clinical studies, only a limited number of therapeutics for GC have been approved to date. Areas covered: In this systematic review of the available literature, we discuss the completed and ongoing clinical trials of molecular targeted therapies in patients with GC, with a focus on their efficacy and safety profiles. Expert opinion: Results of recent studies clearly demonstrated that trastuzumab and ramucirumab, monoclonal antibodies (mAbs) against human epidermal growth factor receptor 2 (HER2) and vascular endothelial growth factor (VEGF), respectively, improved overall survival (OS) in GC with manageable safety profiles. Careful surveillance of ongoing clinical trials and timely profiling and monitoring of genetic signatures are imperative to establish a strong foundation for precision medicine in GC.