P53 expression in multicentric squamous cell carcinoma and surrounding squamous epithelium of the upper aerodigestive tract. Immunohistochemical analysis of 95 lesions.

Abstract

It is now well documented that patients with squamous cell carcinoma of the upper aerodigestive tract frequently develop additional squamous cell carcinoma in the same field. p53 expression in 95 patients with multicentric squamous cell carcinoma and in squamous epithelia surrounding multicentric squamous cell carcinomas of the upper aerodigestive tract in 20 patients was examined by immunohistochemistry. In addition, p53 expression in 129 patients with supposedly unicentric squamous cell carcinoma and in squamous epithelia surrounding unicentric squamous cell carcinoma in 22 patients was also examined by immunohistochemistry. Among the 95 patients with multicentric squamous cell carcinoma, 62 (65%) had a clearly positive reaction for p53 protein, whereas 56 (43%) of 129 patients with unicentric squamous cell carcinoma had a positive reaction for p53 protein. The frequency of positive nuclear p53 staining in multicentric squamous cell carcinoma appeared higher than that in unicentric squamous cell carcinoma. However, there was no significant difference between the two groups. Among the nondysplastic squamous epithelia surrounding multicentric squamous cell carcinomas in 20 patients, 12 (60%) were p53 positive, whereas only five (22%) of 22 patients with nondysplastic squamous epithelia surrounding unicentric squamous cell carcinomas were positive. The difference between the two groups was significant (P < 0.05). The present results suggest that nuclear accumulation of p53 in the squamous epithelium surrounding multicentric squamous cell carcinoma is probably due to heavier exposure and increased susceptibility to mutagens of the affected individuals, although this remains to be verified.