Gastric Intestinal Metaplasia: Challenges and the Opportunity for Precision Prevention

SIMPLE SUMMARY: Gastric adenocarcinoma is the fifth most common cancer worldwide and the fourth most lethal. It is often asymptomatic at an early stage, when survival rates are highest (>90%) with minimally invasive endoscopic intervention or surgery. Gastric intestinal metaplasia (GIM) is a persistent, premalignant lesion in the stomach, arising in the context of chronic inflammation, which predisposes one to gastric cancer. It is considered a pivotal stage along a continuum to gastric cancer and has a median latency period of ~6 years before progression to cancer typically occurs, offering a window of opportunity for intervention. However, only a small proportion (0.25–2.5%) with GIM ultimately progress to cancer; therefore, approaches to surveillance vary widely around the world. We summarise the current evidence supporting best clinical practice in the diagnosis, assessment and management of GIM, and the opportunities to achieve precision in predictions in the coming decades. ABSTRACT: GIM is a persistent, premalignant lesion whereby gastric mucosa is replaced by metaplastic mucosa resembling intestinal tissue, arising in the setting of chronic inflammation, particularly in the context of Helicobacter pylori. While the overall rates of progression to gastric adenocarcinoma are low, estimated at from 0.25 to 2.5%, there are features that confer a much higher risk and warrant follow-up. In this review, we collate and summarise the current knowledge regarding the pathogenesis of GIM, and the clinical, endoscopic and histologic risk factors for cancer. We examine the current state-of-practice with regard to the diagnosis and management of GIM, which varies widely in the published guidelines and in practice. We consider the emerging evidence in population studies, artificial intelligence and molecular markers, which will guide future models of care. The ultimate goal is to increase the detection of early gastric dysplasia/neoplasia that can be cured while avoiding unnecessary surveillance in very low-risk individuals.