Expression of CD44V6 in parotid pleomorphic adenoma and carcinoma ex pleomorphic adenoma

Abstract

Background: Change in expression of CD44 variant (CD44v) has been observed in several types of aggressive carcinomas. This pattern of expression might be associated with carcinogenesis of parotid pleomorphic adenoma (PPA) which is not widely studied. In this study, we aimed to investigate the expression of CD44v6 in the PPA before and after recurrence, between non-recurrent PPA, recurrent PPA, and PPA with carcinogenesis so as to identify whether the expression differences have existed before the recurrence and its significance for predicting the recurrence. Methods: Expression differences of CD44v6 were detected by immunohistochemistry in samples of non-recurrent PPA, PPA before and after the recurrence, carcinoma in pleomorphic adenoma (CPA) and normal parotid. Results: The expression of CD44v6 was significantly higher in the group before the recurrence than that after the recurrence (p < 0.05). The expression of CD44v6 after recurrence was significantly lower than that in the non-recurrent group (p < 0.05) while the high level of CD44v6 expression in the non-recurrent group, was significantly lower than in the group with CPA (p < 0.05). However, no significant difference was observed between the group after recurrence and CPA. Conclusion: The decrease of CD44v6 expression promoted the recurrence and carcinogenesis of PPA, and the expression was decreased further in the process. The expression differences of CD44v6 had appeared before the recurrence.