p53 gene mutants expression, cellular proliferation and differentiation in oesophageal carcinoma and non-cancerous epithelium.

An immunohistochemical study of 155 squamous cell carcinomas of the oesophagus, squamous epithelium adjacent to the tumour (n = 80), dysplastic epithelium (n = 16) and controls (n = 23) indicates that Ki67 and p53 expression is frequently present in premalignant oesophageal lesions and their related squamous cell carcinomas. Positive expression of both antibodies in apparently normal epithelium can signify early steps of malignant transformation of oesophageal epithelium and can serve in the detection of early precancerous lesions. The expression of growth factors EGF and TGF-alpha was higher in carcinomas and dysplastic lesions than in apparently normal squamous epithelium. EGF expression was unevenly distributed according to histological grade, indicating a lack of EGF immunoreactivity in poorly differentiated oesophageal carcinomas.