Ectopic expression of homeodomain protein CDX2 in intestinal metaplasia and carcinomas of the stomach.

The roles of CDX2 and CDX1 homeobox genes during gastric carcinogenesis remain poorly defined. We have studied the expression of CDX2/1 in gastric cancers and intestinal metaplasia (IM) of 69 gastric carcinoma patients by immunohistochemistry. CDX2/1 were shown to be ectopically overexpressed in IM in 41 (85%) of 48, and 47 (90%) of 52 cases, respectively. The expression of CDX2/1 was detected in 38 (55%) and 51 (74%) of the 69 gastric carcinomas, respectively. The histological type of the gastric carcinomas was independently associated with CDX2 expression, but not with that of CDX1, with higher CDX2 expression in intestinal type (differentiated type) than in diffuse type (undifferentiated type) gastric carcinomas. Our results thus suggest that CDX2 and CDX1 may play a role during IM formation and gastric carcinogenesis.