intestinal type

Intestinal-type gastric adenocarcinoma is one of the two major histologic subtypes described in the Lauren classification (the other being diffuse-type). It develops through a well-defined multistep carcinogenesis pathway: chronic H. pylori gastritis → chronic atrophic gastritis → intestinal metaplasia → dysplasia → adenocarcinoma (Correa cascade). This subtype forms recognizable glandular structures and is associated with dietary factors such as high salt intake, nitrosamines (smoked/processed foods), and low fruit/vegetable consumption. It commonly affects the antrum and lesser curvature of the stomach and often presents as an ulcerating mass lesion. Epidemiologically, it is more common in older men and shows geographic variation (high incidence in Japan, Korea, parts of Eastern Europe, and South America), reflecting environmental and dietary influences. In contrast to diffuse-type gastric cancer (associated with CDH1/E-cadherin mutations, signet ring cells, and linitis plastica, occurring in younger patients with familial predisposition), intestinal-type is more sporadic and environmentally driven. Prognosis is generally somewhat better than diffuse-type due to its more organized growth pattern and often more localized presentation. Molecular studies show intestinal-type tumors are linked with chromosomal instability, TP53 mutations, and microsatellite instability in some cases. Treatment involves surgical resection (subtotal or total gastrectomy) with lymphadenectomy, often combined with perioperative chemotherapy or chemoradiation for advanced disease. Recognizing this classification is high-yield for boards as it links chronic H. pylori infection, intestinal metaplasia, and progression to gastric adenocarcinoma—a classic USMLE pathology sequence.