32 Background: Endoscopic submucosal dissection (ESD) is used for the treatment of gastric adenoma as well as early gastric cancer. Gastric adenoma is a well-known precursor of gastric cancer. The aim of this study is to investigate the expression degree of p53 and Ki-67 in gastric adenoma can predict progression to gastric cancer. Methods: We analyzed p53 and Ki-67 expression degree in the tumor tissue of 16 gastric adenoma patients treated by ESD and 11 early gastric cancer patients treated by subtotal gastrectomy at Kangnam Sacred Heart Hospital of Hallym University between November 2008 and May 2009. According to the fraction of stained nuclei in tumor tissue, expression degree was classified as < 10% = negative, 10%∼33% = 1+, 34%∼66% = 2+, > 66% = 3+. Results: Mean age was 65.1 ± 11.5 years and mean tumor size was 33.7 ± 20.2mm. Among 16 gastric adenoma patients, low-grade dysplasia were 11 and high grade dysplasia were 5. p53 positivity was not different between gastric adenoma and gastric cancer, but Ki-67 positivity was significantly different between adenoma and cancer (p < 0.05). In addition, Ki-67 positivity was increasing tendency as the pathology progress from low grade dysplasia to cancer. Conclusions: Ki-67 positivity grade seems to be correlated with malignancy. High Ki-67 positivity in gastric adenoma can predict progression to gastric cancer. Even if endoscopic biopsy showed low grade dysplasia, additional ESD should be preferentially considered in lesions with high Ki-67 positivity. No significant financial relationships to disclose.
Differential Diagnosis of Gastric Adenoma and Type IIA Early Gastric Cancer