Predictors of progression in Barrett's esophagus III: Baseline flow cytometric variables

OBJECTIVES: Barrett's esophagus develops in 5-10% of patients with gastroes ophageal reflux disease and predisposes to esophageal adenocarcinoma. We ha ve previously shown that a systematic baseline endoscopic biopsy protocol u sing flow cytometry with histology identifies subsets of patients with Barr ett's esophagus at low and high risk for progression to cancer. In this rep ort, we further examined cytometric variables to better define the characte ristics that best enable DNA cytometry to help predict cancer outcome. METHODS: Patients were prospectively evaluated using a systematic endoscopi c biopsy protocol, with baseline histological and flow cytometric. measurem ents as predictors and with cancer as the outcome. RESULTS: A receiver operating curve analysis demonstrated that a 4N fractio n cut point of 6% was optimal to discriminate cancer risk (relative risk [R R] = 11.7, 95% CI = 6.2-22). The 4N fractions of 6-15 % were just as predic tive of cancer as were fractions of > 15%. We found that only aneuploid DNA contents of >2.7N were predictive of cancer (RR = 9.5, CI = 4.9-18), where as those patients whose sole abnormality was an aneuploid population with D NA content of less than or equal to2.7 had a low risk for progression. The presence of both 4N fraction of >6% and aneuploid DNA content of >2.7N was highly predictive of cancer (RR = 23, CI = 10-50). S phase was a predictor of cancer risk (RR = 2.3, CI = 1.2-4.4) but was not significant when high-g rade dysplasia was accounted for. CONCLUSIONS: Flow cytometry is a useful adjunct to histology in assessing c ancer risk in patients with Barrett's esophagus. Careful examination of cyt ometric variables revealed a better definition of those parameters that are most closely associated with increased cancer risk. troenterol (C) 2001 by Am. Coll. of Gastroenterology.