Microsatellite instability of gastric cancer and precancerous lesions.

OBJECTIVE To investigate whether microsatellite instability (MSI) of gastric cancer and precancerous lesions were existed and its effect. METHODS Laser microdissection was used. Gastric, intestinal metaplasia, dysplasia and normal mucosa were collected respectively. Five microsatellite loci were selected and MSI was detected by denaturing high-performance liquid chromatography. RESULTS In the five microsatellite loci REF-positive phenotype, intestinal metaplasia MSI was 20.7%. Dysplasia MSI was 22.4%. Gastric MSI was 47.9%, and there was no MSI in normal gastric mucosa. CONCLUSION MSI gradually increased from precancerous lesions to gastric cancer. The early detection of MSI may be a potential early warning indicator for early diagnosis of gastric cancer.