Immunohistochemical study of p53, EGF, EGF-receptor, v-erb B and ras p21 in squamous cell carcinoma of hypopharynx.

ABSTRACT

We have characterized 24 hypopharyngeal squamous cell carcinomas and 5 normal hypopharyngeal tissues by immunostaining with antibodies against epidermal growth factor (EGF), EGF-Receptor (EGFR), p53, v-erb B, and ras p21. The Avidin-Biotin Complex (ABC) technique was employed. Overexpression of p53 appeared in 17 of 24 cases of squamous cell carcinoma of the hypopharynx (normal mucosa none, well differentiated 60%, moderately differentiated 71.4%, poorly differentiated 71.4%). Some dysplastic mucosae surrounding cancer lesions showed overexpression of p53. EGF and EGFR tended to be expressed more strongly in carcinoma [EGF 29.1% (well differentiated 30%, moderately differentiated 28.6%, poorly differentiated 28.6%); EGFR 50% (well differentiated 60%, moderately differentiated 42.9%, poorly differentiated 42.9%)] than in normal mucosa (EGF 0%, EGFR 20%). The v-erb B stained positively in carcinoma [62.5% (well differentiated 70%, moderately differentiated 71.4%, poorly differentiated 42.9%)] but negatively in normal mucosa. These data suggest that genetic mutations of p53 probably play an important role at an early stage of tumorigenesis, and that the networks of EGF, EGFR and v-erb B probably are involved in the development of hypopharyngeal squamous cell carcinoma.