Expression of CDX2 protein in gastric mucosa with intestinal metaplasia and gastric carcinoma

Background: CDX2 is a caudal homeobox gene essential for intestinal proliferation and differentiation. Expression of its protein product CDX2 in gastric mucosa is strongly associated with intestinal metaplasia and gastric carcinoma. Objectives: 1. To study the incidence of intestinal metaplasia in gastric cancer 2.To study the expression of CDX2 protein in intestinal metaplasia and gastric carcinoma. Materials and Methods: The study was done for a period of 11/2 years on 50 gastrectomies. The gastric cancer was typed according to Lauren’s classification. Adjacent mucosa was assessed and those with intestinal metaplasia were typed into type I, II and III by histochemistry. Immunohistochemistry for CDX2 was done in all cases of intestinal metaplasia and corresponding gastric carcinomas.The staining was graded semiquantitatively and statistical analysis was done. Results: There were 34(68%), 9(18%) and 6(12%) cases of intestinal, diffuse and mixed type of gastric adenocarcinoma respectively. The most frequent change in adjacent mucosa was chronic gastritis with intestinal metaplasia. CDX2 immunostaining was positive in 24 out of the total 27 cases (88.8%) of intestinal metaplasia and 21 out of 27 cases (77.7%) of gastric cancer. All controls (100%) turned out to be negative, making the above observations statistically significant. Conclusions: Chronic gastritis with intestinal metaplasia is the commonest precursor lesion of gastric adenocarcinoma. CDX2 homeodomain protein which is not expressed in normal gastric mucosa is a sensitive marker for intestinal metaplasia and is closely associated with intestinal type of adenocarcinoma.