Gastric cancer is one of the most common and potentially lethal gastrointestinal malignancy, but it is now at the forefront of modern oncology due to new discoveries.  In recent years, the field of gastric cancer has been transformed by many notable developments in both the diagnostic area and the therapeutic strategies.<div> </div><div>The main aim of the text is to propose a comprehensive, state-of-the art review of this field, and will serve as a valuable resource for oncologists, pathologists, surgeons and researchers with an interest in gastric cancer.  The first chapters will review the interplay between pathogens and especially H. pylori, inflammation, genomic instability, and tumorigenesis. Secondly, an exhaustive overview of the diagnosis of gastric cancer from a clinical/endoscopic and pathologic perspectives will be illustrated.