CDX2, COX2 and MUC2 expressions in Barrett's esophagus: can they be useful in determination of the dysplasia?

OBJECTIVE The description of Barrett's esophagus which is a risk factor for esophageal adenocarcinoma has differences, and the need of goblet cells for diagnosis is controversial. However, the pathophysiology in the metaplasia seen in Barrett's esophagus is not totally understood and new methods are searched for the assessment of progression to dysplasia. We aimed to search the immunohistochemical expression of CDX2, COX2 and MUC2 in Barrett's esophagus to detect any early evidence of intestinal metaplasia or dysplasia. MATERIAL AND METHOD The staining properties were examined in the intestinal metaplastic (goblet cell-containing columnar epithelium), columnar (non-goblet columnar epithelium), distant columnar (non-goblet columnar epithelium distant from intestinal metaplastic epithelium) and squamous epithelium in 59 pathologically diagnosed Barrett's esophagus, 22 of which having dysplasia. The results were compared statistically with Pearson and Fisher exact tests. RESULTS The distribution of the staining of intestinal metaplastic, non-goblet columnar distant columnar, and squamous epithelium, respectively were as follows: for CDX2 76.3%, 23.7%, 1.7%, 0%; for COX-2 93.2%, 47.5%, 8%, 62.9%; for MUC2 93.2%, 11.9%, 4% and 0%. The expression of CDX2, COX2 and MUC2 in the intestinal metaplastic epithelium was higher than the expression in distant and non-goblet columnar epithelium. The expression of CDX2, COX2 and MUC2 in the foci of dysplasia decreased significantly (18.2%, 27.3%, 31.9%, and p=0.039, 0.0001, 0.0001, respectively). COX2 expression in squamous epithelium was also lower when the adjacent mucosa has dysplasia (p=0.014). CONCLUSION The CDX2, COX2 and MUC2 expressions were seen in the intestinal epithelium having goblet cells. The use of the markers in the diagnosis is controversial but the difference in the Barrett esophagus-dysplasia sequence seems to be meaningful.