RESUMO
Actinic keratosis is a precancerous lesion of the skin with variable rates of transformation into non-melanocytic carcinomas. The present study aims to analyze p21 expression in actinic keratosis and cutaneous squamous carcinomas. P21 expression analysis revealed a positive reaction in 63 (71.4%) of the investigated cases. The immunostaining analysis revealed positivity in 82.1% of the studied actinic keratosis cases and in 43.9% of the investigated carcinomas. High scores of immunoreactions were identified only for the well-differentiated and for the carcinomas in initial stages. Association of p21 expression with pre-invasive or well-differentiated invasive lesions in early stages of tumor progression suggests that p21 may be an early event in squamous carcinogenesis.
RESUMO
CD44 seems to confer the needed conditions for malignant neoplasms to grow and progress. The present study aims to investigate the role of CD44 expression in pre-invasive and invasive squamous lesions of the skin. We investigated 89 cases of preinvasive and invasive cutaneous lesions, of which 28 corresponded to actinic keratosis (KIN- keratinocyte intraepithelial neoplasia) with varying degrees of severity and 61 cases of squamous cell carcinoma with variable degrees of differentiation. The statistical analysis of CD44 immunoexpression indicated significantly higher values for KIN I and II compared to KIN III, as well as for KIN lesions in comparison with squamous cell carcinomas. Similar results were observed in well differentiated carcinomas compared to moderate and poorly differentiated lesions. These observations suggest that CD44 expression plays a role in the progression of cutaneous squamous neoplasia.
RESUMO
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.
