Aberrant expression of E-cadherin in cervical intraepithelial neoplasia correlates with a false-negative Papanicolaou smear

OBJECTIVES: E-cadherin is responsible for cell adhesion in normal cervical epithelium. It is normally absent in the superficial epithelial layers, allowing for exfoliation. We investigated the correlation between E-cadherin distribution and Papanicolaou smear in subjects with cervical dysplasia. STUDY DESIGN: Tissue samples from 25 women with cervical dysplasia were tested for E-cadherin, beta-catenin, and alpha-catenin expression by immunohistochemistry. The expression pattern of these proteins, whether full thickness or restricted to the basal layers, was correlated with the Papanicolaou smear result. RESULTS: Of 12 women with normal Papanicolaou smears, 10 of 11 informative cases demonstrated E-cadherin expression throughout all epithelial layers. Eight of 10 informative cases with an abnormal Papanicolaou smear showed E-cadherin only at the basal layers. Alpha-catenin was distributed throughout the entire epithelium in samples of all 25 women. CONCLUSIONS: Expression of E-cadherin throughout all epithelial layers was correlated with a false-negative Papanicolaou smear. It is likely that aberrant persistence of E-cadherin in these lesions interferes with the exfoliation of abnormal cells.