Educational Articles
Gastric Intestinal Metaplasia in High Risk Population
Gastric cancer is the most frequent cancer affecting Koreans. According to one official Korean survey conducted in 1993, among all cancers affecting Koreans, 27.5% are due to gastric cancer. In fact, the overall life-time risk of developing gastric cancer for Koreans is thought to be as high as 6-7% according to some estimate. Recent change in diet and improvement in hygiene, as well as the discovery and initiation of treatment of H. pylori infection are expected to result in the overall reduction in the incidence of gastric cancer. However, despite rapid advances in medicine, 7 out of 10 individuals diagnosed with gastric cancer still do not survive beyond 5 years, as most cancers are diagnosed at a late stage. Thus, early diagnosis of gastric cancer remains urgent health issue for those affected.
Normal Stomach
Intestinal Metaplasia
The gold standard in the diagnosis of gastric cancer remains upper endoscopy. It allows a complete visual evaluation of the inner lining of stomach (gastric mucosa). If necessary, endoscopy also permits biopsy study for further evaluation of the stomach lining under the scrutiny of microscope.
In cases where the diagnosis of gastric cancer is excluded by a "normal" upper endoscopy, the risk of eventual development of cancer is not completely excluded. In fact, there are certain subtle endoscopic features or findings that would prompt endoscopist to take biopsy samples, even if frank cancer is not suspected. When these biopsy specimen do reveal microscopic pre-malignant findings such as intestinal metaplasia, and dysplasia, a careful follow-up becomes paramount, particularlly in high risk individuals.
Intestinal Metaplasia under microscope
The finding of gastric intestinal metaplasia indicate that the gastric lining has undergone transformation from normal gastric cell type to those that resemble "intestine." This finding of intestinal metaplasia from the biopsy of gastric mucosa indicates an increased potential to eventually develop gastric cancer in affected individuals, particularly among the high risk population. In fact, according to one study, the risk of developing gastric cancer in patients with intestinal metaplasia may be as high as 0.5% to 1.0% per year among the high risk population. The finding of dysplasia portend even higher risk of eventually developing gastric cancer.
Asymptomatic Korean patients are advised to undergo biennial endoscopic surveillance starting at the age of 40, because of the high ethnic risk of developing gastric cancer. For patients with the endoscopic finding of gastric metaplasia, decreasing this interval to yearly frequency is recommended. When more ominous dysplasia is detected, decreasing the follow-up interval to 6-12 months should be considered. Careful endoscopic follow-up evaluation is expected to help establish the diagnosis of gastric cancer at an earlier stage, and help extend the lives of those who are unfortunately affected by this deadly disease.
