P53 and MDM2 protein expression in squamous cell carcinoma and neighboringdysplasia from the upper aerodigestive tract

Background: The identification of genetic changes in preinvasive epithelial lesions may provide markers for a better assessment of the progression pot ential. Materials and methods. p53, MDM2 and PCNA immunophenotypes were exa mined in 57 cases of squamous cell carcinoma (SCC) of the upper aerodigesti ve tract and the adjacent normal and dysplastic epithelia. Results: PCNA in dex increased with increasing grade of dysplasia. p53 protein was expressed in 35% and MDM2 protein in 33% of SCCs. The p53 protein was expressed in 8 9% of mild and moderate and in 93% of severe dysplasia and carcinoma in sit u adjacent to p53-positive SCCs. The MDM2 protein was expressed in 30% of m ild and moderate and in 54% of severe dysplasia and carcinoma in situ adjac ent to MDM2-positive SCCs. Preinvasive lesions adjacent to negative SCCs st ained negative. Conclusions: p53 protein was detected more frequently in pr einvasive lesions than MDM2 protein and seems to be of greater value as a b iomarker.