Expression and importance of zinc-finger transcription factor Slug in adenoid cystic carcinoma of salivary gland

Background: It has been reported that zinc-finger transcription factor Slug plays a critical role in tumor proliferation and differentiation, relapse, invasion, metastasis, and decreased survival. However, there is little information on the expression and role of Slug in salivary adenoid cystic carcinoma (ACC). Method: Demographic variables and primary tumor site, dates of diagnoses, perineural invasion, local regional recurrence, and distant metastasis of 121 cases of salivary ACC treated at the Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University between 1996 and 2005 were retrieved. The Slug expression of all these cases was examined by immunohistochemical methods. The association between Slug expression and clinicopathological variables was analyzed using Chi-squared test, and the prognostic factors were examined by univariate and multivariate analyses. Results: Our data demonstrated that the positive expression of Slug was observed in 71.90% (87/121) of cases. Slug expression was significantly associated with tumor site, TNM stage, histological pattern, perineural invasion, local regional recurrence and distant metastasis of patients with ACC (P < 0.05). And Slug expression, local regional recurrence and distant metastasis were independent and significant prognostic factors in all patients. Conclusions: It is proposed that Slug may play an important role in the invasion and metastasis of ACC, and that Slug had the potential for one of the strong invasion and metastasis indicators at presentation of ACC patients.