Immunohistochemical expression of cathepsin D in laryngeal epithelial lesions: Correlation with CD44 expression, p53 and Rb status and proliferation associated indices

Clinical studies in several tumour. types have shown a strong con elation b etween cathepsin D expression and tumour progression. Immunohistochemical s taining for cathepsin D (clone D13A) was performed in paraffin embedded tis sues from 39 invasive squamous cell carcinomas, 13 in situ carcinomas 35 ca ses of dysplasia, 10 papillomas and 17 cases of keratosis. The association between cathepsin D expression and CD44, p53, Rb proteins and proliferation indices (Ki-67, PCNA) was assessed by univariate analysis. Cathepsin D was highly positive-ii; the groups of carcinomas compared to other lesions (p< 0.0001). A statistically significant correlation of cathepsin D expression with CD44 expression was observed in invasive cancers (p=0.037). The relati onship of cathepsin D immunoreactivity with p53, Rb and proliferation indic es was insignificant. The results show that cathepsin D is expressed in a h igher proportion of cancerous lesions of the larynx than in non cancerous o r premalignant lesions, a fact which suggests that cathepsin D may be invol ved in laryngeal armour cell growth process.