ABSTRACT
BACKGROUND: 81 patients with tongue carcinomas were studied to determine: 1). the proportion of carcinomas with altered p16 expression; 2). whether loss of p16 is an early carcinogenic event; 3). whether p16 expression alterations influence the prognosis. METHODS: 50/81 cases could be analysed by immunohistochemistry. RESULTS: Tumours were p16- in 32% (16/50) and p16+ in 68% (34/50) of patients; 32.3% (11/34) of p16+ tumours presented 1-10% of tumour cells as positive, 14.7% (5/34) 11-40% as positive, and 59.2% (18/34) presented 41-100% of tumour cells as positive. Adjacent nontumoural epithelium (ANTE) was available in 33 of the 50 immunohistochemically analysed specimens. ANTE was normal in 25 cases and dysplastic in 8 cases. In normal ANTE, p16 expression was positive in 16% (4/25) and negative in 84% (21/25) of cases. p16 expression was negative in all dysplastic ANTE samples (8/8). CONCLUSIONS: Changes in p16 expression are frequent in tongue cancer and can be detected at very early stages of carcinogenesis. Nevertheless, in our study neither the absence nor the degree of p16 expression influenced the survival of patients.
