A 58-year-old Indian man with a 10-year history of chronic epigastric pain and H. pylori infection presents with progressive dysphagia and weight loss. Endoscopy reveals a large ulcerated lesion in the antrum. What is the most common site of gastric carcinoma in this patient?

Explanation

## Anatomical Distribution of Gastric Carcinoma **Key Point:** The antrum and lesser curvature (pyloric region) are the most common sites of gastric carcinoma, accounting for 50–60% of all gastric cancers. ### Frequency by Site | Site | Frequency | Clinical Notes | | --- | --- | --- | | **Antrum and lesser curvature (pyloric region)** | 50–60% | Most common; often associated with H. pylori and chronic gastritis | | **Fundus and greater curvature** | 20–25% | Second most common; often associated with intestinal-type adenocarcinoma | | **Cardia and GE junction** | 10–15% | Associated with Barrett's esophagus and reflux; adenocarcinoma predominates | | **Body of stomach** | 5–10% | Least common; variable histology | **High-Yield:** The antrum is the most common site because: 1. It is the site of maximal H. pylori colonization and chronic inflammation. 2. The lesser curvature has the richest lymphatic drainage, facilitating early spread. 3. The antral mucosa is most susceptible to intestinal metaplasia and dysplasia following chronic gastritis. ### Clinical Correlation **Clinical Pearl:** Antral cancers often present with: - Pyloric obstruction → early satiety, vomiting, weight loss - Ulceration → chronic blood loss → iron-deficiency anemia - Advanced stage at diagnosis (due to late presentation) The patient in this vignette has classic features of antral gastric cancer: chronic H. pylori infection, dysphagia (from pyloric involvement), weight loss, and an ulcerated lesion in the antrum on endoscopy. **Mnemonic:** **ANTRUM = Antral site (most common), Nodal spread (early), Toxic H. pylori (driver), Routine presentation (dysphagia, weight loss), Ulceration (common), Metaplasia (precursor)** ### Pathogenesis Link The Correa cascade progresses most aggressively in the antrum because: - H. pylori preferentially colonizes the antral mucosa (less acidic environment than fundus). - Chronic antritis leads to loss of acid-secreting parietal cells → hypochlorhydria → further H. pylori proliferation. - Intestinal metaplasia develops in the antrum before other regions.