Proliferating cell nuclear antigen in the assessment of Barrett's mucosa.

Proliferating cell nuclear antigen (PCNA) expression was assessed in oesophageal epithelium from 70 patients with Barrett's oesophagus. PCNA counts were expressed in the form of a PCNA index. There were 24 patients with dysplastic epithelium, nine with regenerative atypia, 18 with benign histology and 19 with adenocarcinoma arising in Barrett's epithelium. The PCNA index of malignant tissue was significantly different from that of benign (P < 0.001) and dysplastic (P < 0.05) specimens. PCNA indices in histologically normal Barrett's epithelium adjacent to a tumour were significantly different (P < 0.001) from those in normal Barrett's epithelium with no adjacent tumour. These findings support the use of PCNA measurement in the assessment of Barrett's epithelium.