Glycoprotein CD44 expression in benign, premalignant and malignant epithelial lesions of the larynx: An immunohistochemical study including correlation with Rb, p53, Ki-67 and PCNA

CD44 is an integral membrane glycoprotein that has diverse functions in cel l-cell and cell-substrate interactions. It has been suggested that it may b e a determinant of metastatic and invasive behavior in carcinomas. The immu nohistochemical expression of CD44 was examined in a series of 34 squamous cell carcinomas, 13 in situ carcinomas, 35 cases with various degrees of ep ithelial dysplasia, 10 papillomas and 17 cases of keratosis. We used the mo noclonal mouse antihuman phagocytic glycoprotein-l CD44 (clone DF 1485), on formalin-fixed, paraffin-embedded tissue. CD44 expression was correlated w ith the expression of Rb and p53 proteins, with the proliferative indices K i-67 and PCNA as well as with conventional clinicopathological data. The me an value of CD44 expression was 78.84 in squamous cell carcinomas, 78.04 in in situ carcinomas, 54.93 in dysplasia, 26.8 in papillomas and 24.97 in ke ratosis. There was no significant difference of CD44 expression between in situ and invasive carcinomas. However, a strong difference of reaction betw een carcinomas and the other cases was observed. CD44 expression was statis tically higher in dysplastic lesions than the cases of keratosis (p<0.0001) and papillomas (p=0.01). In the group of invasive carcinomas, CD44 express ion was statistically correlated with pRb (p=0.011), while in preinvasive l esions it was correlated with PCNA (p=0.016). The relationship with the deg ree of dysplasia or grade of carcinoma and p53 protein expression was insig nificant. These observations suggest that CD44 expression may be involved in the mult iple mechanism of the development and progression of laryngeal lesions and may help to predict the risk of transformation of the benign or precancerou s lesions to cancer.