Analysis of p53 Mutations and the Expression of p53 and p21WAF1/CIP1Protein in 15 Cases of Sebaceous Carcinoma of the Eyelid

Abstract

Purpose.: The purpose of this study was to detect mutation of the p53 gene, to assess its relationship with p53 or p21^WAF1/CIP1 expression, and to evaluate the correlation between p53 mutation or p21^WAF1/CIP1 expression and clinicopathologic findings in sebaceous carcinoma of the eyelid. Methods.: Fifteen conventional paraffin-embedded samples of sebaceous carcinoma of the eyelid were analyzed. Using the single-strand conformation polymorphism technique, the authors sequenced coding exons 5–8 of the p53 gene. The expression of p53 and p21^WAF1/CIP1 protein was analyzed by immunohistochemistry. Results.: In 10 of the 15 cases (66.7%), point mutations were detected in the p53 gene. CC to TT double-base changes (tandem mutations), which are known to be induced only by UV, were not detected in any of the mutations. Correlations between p53 mutation and expression were found to be statistically significant (P = 0.007). There was no significant correlation between p53 mutation and clinicopathologic findings or p21^WAF1/CIP1 expression. However, there was a significant inverse correlation between p21^WAF1/CIP1 expression and presence of lymph node metastasis (P = 0.007). Conclusions.: Among human cancers, sebaceous carcinoma of the eyelid may be one of those showing most frequent mutation of the p53 gene, which may not be caused by exposure to UV. p21^WAF1/CIP1 downregulation may be associated with lymph node metastasis.