A variety of prognostic markers have been related to decreased patient survival in patients with epithelial malignancies. These include expression of the homotypic adhesion molecule E-cadherin (ECAD) and the hyaluronic acid receptor CD44. Expression of ECAD and CD44 was evaluated in Barrett's-associated adenocarcinoma (BAd) from 67 patients. Expression was determined by immunoperoxidase staining and graded semiquantitatively based on the proportion of positively stained cells. These data were then correlated with clinical and pathological parameters, including the presence or absence of chemoradiotherapy (chemrad) and patient survival. There were 56 men and 11 women (mean age, 62 years). Thirty-nine (58%) patients received preoperative chemrad. ECAD expression was detected in all (100%) tumors. The ECAD staining grade did not correlate with other pathological features of the tumors. However, ECAD staining was significantly increased in BAd of patients who received chemrad (P = .003), in comparison with those who did not, and in individual patients when prechemrad biopsies and postchemrad resection specimens were compared (P = .04). In terms of prognosis, increased ECAD expression was associated with shortened patient survival only in BAd patients who had received chemrad (univariate analysis of chemrad patients with stage I and II BAd, P = .02). ECAD expression was not significantly associated with survival in BAd patients who did not receive chemrad. CD44 expression was detected in 88% of cases. CD44 expression did not correlate with any of the pathological features of the tumors or with chemrad status. Increased expression of CD44 was significantly associated with shortened patient survival in chemrad patients only (univariate analysis P = .03, multivariate analysis P = .04), although a strong trend was observed when all patients were analyzed regardless of chemrad status (P = .07). The results of this study indicate that chemrad alters the expression of ECAD in BAd. Thus, the prognostic utility of ECAD expression must be evaluated in the context of chemrad status. CD44 also may be a valuable prognostic marker in BAd.