P53 EXPRESSION DURING MULTISTAGE HUMAN ORAL CARCINOGENESIS

This study examined the immunohistochemical expression of p53 in human oral premalignancies and squamous cell carcinomas (SCC), and analyzed the relationship between the expression of p53 and the degree of dysp lasia. p53 staining was observed in 15 of the 27 oral premalignant les ions (56%), including mild dysplasia, and 7 of the 10 oral SCC (70%), but in none of the 10 hyperplastic oral lesions. With increasing degre es of dysplasia and the appearance of SCC, not only was there an incre ase in the percentage of cases demonstrating p53 staining, but also an increase in the staining intensity of the positive cells and expansio n of these positive cells. The results suggest that mutation of p53 is an early event during oral cancer development and p53 protein may be used as an early adjunct marker for identification of those premaligna nt lesions with higher malignant potential.