Gastric cancer remains the third leading cause of cancer-related mortality globally, with an estimated 1 million new cases in 2008, primarily concentrated in Eastern Asia, Eastern Europe, and South America. The case fatality rate is higher in these regions compared to industrialized countries. At diagnosis, two-thirds of patients present with advanced disease, leading to a 5-year survival rate below 30%. Gastric cancers are a heterogeneous group of malignant epithelial lesions, with over 95% being adenocarcinomas, primarily intestinal or diffuse histotypes. Intestinal-type gastric cancer, accounting for 50-70% of cases, is associated with Helicobacter pylori (H. pylori) infection. Historically, gastric cancer has been recognized since ancient times, with Hippocrates using the term "cancer" for a stomach malignancy. In the 19th century, anatomical descriptions and connections between gastric ulcer and cancer emerged. The 20th century saw significant advancements in histopathology and endoscopy, leading to the identification of chronic gastritis as a key factor in gastric cancer development. The discovery of H. pylori as a cause of chronic gastritis in 1983 further explained the epidemiological characteristics of gastric cancer. The Lauren classification, proposed in 1965, categorizes gastric cancers into intestinal and diffuse histotypes. The intestinal histotype, driven by H. pylori, follows a multistep progression from inflammation to mucosal atrophy and eventually to invasive adenocarcinoma. The decline in gastric cancer cases has been observed, particularly in the intestinal histotype, but not in the diffuse type.Gastric cancer remains the third leading cause of cancer-related mortality globally, with an estimated 1 million new cases in 2008, primarily concentrated in Eastern Asia, Eastern Europe, and South America. The case fatality rate is higher in these regions compared to industrialized countries. At diagnosis, two-thirds of patients present with advanced disease, leading to a 5-year survival rate below 30%. Gastric cancers are a heterogeneous group of malignant epithelial lesions, with over 95% being adenocarcinomas, primarily intestinal or diffuse histotypes. Intestinal-type gastric cancer, accounting for 50-70% of cases, is associated with Helicobacter pylori (H. pylori) infection. Historically, gastric cancer has been recognized since ancient times, with Hippocrates using the term "cancer" for a stomach malignancy. In the 19th century, anatomical descriptions and connections between gastric ulcer and cancer emerged. The 20th century saw significant advancements in histopathology and endoscopy, leading to the identification of chronic gastritis as a key factor in gastric cancer development. The discovery of H. pylori as a cause of chronic gastritis in 1983 further explained the epidemiological characteristics of gastric cancer. The Lauren classification, proposed in 1965, categorizes gastric cancers into intestinal and diffuse histotypes. The intestinal histotype, driven by H. pylori, follows a multistep progression from inflammation to mucosal atrophy and eventually to invasive adenocarcinoma. The decline in gastric cancer cases has been observed, particularly in the intestinal histotype, but not in the diffuse type.