This book provides a comprehensive, state-of-the art review and serves as an overview of the different aspects of gastric cancer. The first section aims to clarify the main aspects of tumorigenesis, such as the role of inflammation linked to the presence of H. Pylori infection, and the genetic and epigenetic mechanisms so far known. Secondly, an exhaustive overview of the diagnosis of gastric cancer from a clinical/endoscopic and pathologic perspective will be illustrated. The second section includes the pathological and clinical features and contains information regarding the most recent tissue and serological biomarkers in these neoplasms. The three successive sections are intended to provide the "state of art" of multimodal treatment approaches to gastric cancer, i.e. standard and novel surgical aspects, common and innovative chemo and radio protocols and modern targeted therapies. Novel molecular classifications are under consideration to improve diagnostic and prognostic definitions and to prospect future treatments based on the use of immunotherapies and innovative molecules such as non-coding RNA and nanoparticles. Gastric Cancer in the Precision Medicine Era serves as a useful resource for physicians and researchers dealing with, and interested in, this challenging malignancy. It provides a concise yet comprehensive summary of the current status of the field that helps guide patient management and stimulates investigative efforts. All chapters are written by experts in their fields and includes the most up to date scientific and clinical information.