Immunohistochemical Evaluation of p53 and Ki67 Expression in Skin Epithelial Tumors

BACKGROUND AND AIMS: The cellular mechanisms responsible for initiating or limiting the tumors including skin types are of great importance. The p53 is a tumor-inhibiting gene which is believed to be defective in many malignant situations. Ki67 is a non-histonic protein which is mainly interfere with the proliferation and has many controlling effects during the cell cycle. Because of their importance in skin tumor cell growth, this study aimed at evaluating the p53 and Ki67 expression in skin epithelial tumors by immunohistochemical method. MATERIALS AND METHODS: In a descriptive setting, 50 biopsy samples (30 basal cell carcinomas (BCCs), 10 squamous cell carcinomas (SCCs), 8 keratoacanthomas (KAs), and 2 trichoepitheliomas (TEs)) were immunohistochemically evaluated for p53 and Ki67 expression during a 14-month period. The incidence and expression rate of these two variables were separately reported in each group of samples. RESULTS: The expression rate of p53 was 67.77% for the BCCs, 50.20% for the SCCs, and null for the KAs. For both TEs, it was 50%. The expression rate of Ki67 was 57.33% for the BCCs, 47.70% for the SCCs, 37.5% for the KAs, and 0.0% for TEs. The incidence of P53+ cells was 100% and 90% in the BCC and SCC samples, respectively. The both TEs were positive in this regard. The incidence of Ki67+ cells was 100% for the BCC, SCC, and KA samples. The both TEs were negative in this regard. CONCLUSION: This study showed that the incidence rate of p53- and Ki67-positive cells is very high in skin malignant epithelial tumors. The expression rate of these two variables is comparable with reports in the literature. Further studies with large sample size are recommended to be carried out for KA and TE samples.