Gastric cancer remains the third leading cause of cancer-related death globally, with a high mortality rate in certain regions. In 2008, over a million new cases were reported, with two-thirds occurring in Eastern Asia, Eastern Europe, and South America, where the case fatality rate was 78%, compared to 65% in industrialized countries. At diagnosis, nearly half of gastric cancer patients have advanced disease, with a 5-year survival rate below 30%. Gastric cancers are a heterogeneous group of malignant epithelial lesions, with over 95% being adenocarcinomas, classified into intestinal and diffuse histotypes. Intestinal-type gastric cancer is the most common, accounting for 50–70% of cases, and is associated with Helicobacter pylori infection. Historically, gastric cancer was first described by Hippocrates in the fourth century BC. In the 19th century, anatomical descriptions of gastric malignancies were made, and in the early 20th century, histopathology advanced with techniques like intragastric formalin administration. In the mid-20th century, chronic atrophic gastritis was identified as a "cancerization field." With the advent of endoscopy and in vivo histology, the understanding of gastric cancer and its precursors expanded. Correa proposed a "multi-step/multi-factorial oncogenic cascade" based on epidemiological studies. In 1983, Warren and Marshall identified H. pylori as the cause of chronic gastritis, leading to the recognition of gastric cancer as an infectious disease. This infectious trait explains many epidemiological features of gastric cancer and supports prevention strategies. The Laurén classification, introduced in 1965, distinguishes between intestinal and diffuse histotypes, with intestinal-type being the most common globally. The intestinal histotype is associated with H. pylori and a multistep progression from chronic inflammation to cancer. The diffuse histotype is less common and has a different etiology.Gastric cancer remains the third leading cause of cancer-related death globally, with a high mortality rate in certain regions. In 2008, over a million new cases were reported, with two-thirds occurring in Eastern Asia, Eastern Europe, and South America, where the case fatality rate was 78%, compared to 65% in industrialized countries. At diagnosis, nearly half of gastric cancer patients have advanced disease, with a 5-year survival rate below 30%. Gastric cancers are a heterogeneous group of malignant epithelial lesions, with over 95% being adenocarcinomas, classified into intestinal and diffuse histotypes. Intestinal-type gastric cancer is the most common, accounting for 50–70% of cases, and is associated with Helicobacter pylori infection. Historically, gastric cancer was first described by Hippocrates in the fourth century BC. In the 19th century, anatomical descriptions of gastric malignancies were made, and in the early 20th century, histopathology advanced with techniques like intragastric formalin administration. In the mid-20th century, chronic atrophic gastritis was identified as a "cancerization field." With the advent of endoscopy and in vivo histology, the understanding of gastric cancer and its precursors expanded. Correa proposed a "multi-step/multi-factorial oncogenic cascade" based on epidemiological studies. In 1983, Warren and Marshall identified H. pylori as the cause of chronic gastritis, leading to the recognition of gastric cancer as an infectious disease. This infectious trait explains many epidemiological features of gastric cancer and supports prevention strategies. The Laurén classification, introduced in 1965, distinguishes between intestinal and diffuse histotypes, with intestinal-type being the most common globally. The intestinal histotype is associated with H. pylori and a multistep progression from chronic inflammation to cancer. The diffuse histotype is less common and has a different etiology.