P53, p16 and Ki67 immunoexpression in cutaneous squamous cell carcinoma and its precursor lesions.

: The incidence of cutaneous squamous cell carcinoma (CSCC) and its precursor lesions argues the research for validating markers that would define the biomolecular mechanisms behind the potential progression and aggressiveness of these lesions. In this study, we analyzed the expression of p53, p16 and Ki67 in 91 cases of CSCC and its precursors in relation with the histological prognostic parameters. The quantification of the immunohistochemical reactions indicated superior significant differences for the studied markers in squamous cell carcinomas compared to keratinocytic intraepithelial neoplasia (KIN). P16 and Ki67 immunostaining for Bowen's disease were similar to those from poorly differentiated carcinomas. In this study, we found significant differences in p53 expression in relation to tumor grading and p16 expression in relation to tumor staging. Ki67 showed higher values in high-grade and advanced stage carcinomas. Positive reactions in preinvasive lesions as well as in CSCC support the sequential development and p53 and p16 involvement from the early stages of skin carcinogenesis.