Distribution of proliferating-cell nuclear antigen and epidermal growth factor receptor in intraepithelial squamous cell lesions of human bronchus.

Distribution of proliferating-cell nuclear antigen and epidermal growth-factor receptor was studied by immunohistochemistry in intraepithelial squamous cell lesions of human bronchus. Ten biopsy specimens were examined for each of the following categories of lesions (50 specimens altogether): normal bronchial epithelium, benign squamous metaplasia, dysplastic squamous metaplasia, and squamous cell carcinoma in situ, in addition to invasive squamous cell carcinoma. The percentage positivity of immunoreactive cells and their localization in the epithelium were examined in formalin-fixed, paraffin-embedded tissues of bronchial biopsy specimens retrieved from the surgical pathology file. Proliferating-cell nuclear antigen positivity ranged from 3.2% (normal bronchial epithelium), to 7.6% (benign squamous metaplasia), 51.8% (dysplastic squamous metaplasia), and 85.0% (squamous cell carcinoma in situ). The difference between the groups was statistically significant (p < 0.01). The percentage positivity for invasive squamous cell carcinoma was 56.9%. Epidermal growth-factor receptor positivity ranged from 7.3% (normal bronchial epithelium), to 38.7% (benign squamous epithelium), 67.5% (dysplastic squamous metaplasia), and 91.3% (squamous cell carcinoma in situ). The difference between the groups was statistically significant (p < 0.01). Invasive squamous cell carcinoma positivity was 49.7%. Both proliferating-cell nuclear antigen-positive and epidermal growth-factor receptor-positive cells showed zonal distribution in the bronchial epithelium. They were located in the basal cell layer in normal bronchial epithelium and expanded upward as the morphologic changes advanced. In squamous cell carcinoma in situ, both proliferating-cell nuclear antigen-positive and epidermal growth-factor receptor-positive cells covered the entire thickness of the bronchial epithelial layer.(ABSTRACT TRUNCATED AT 250 WORDS)