KiSS-1 expression in oral squamous cell carcinoma and its prognostic significance

Downregulated expression of KiSS-1 has been correlated with tumor progression, metastasis, and patient prognosis in various human malignancies. However, there is no information regarding the expression of KiSS-1 in oral squamous cell carcinoma (OSCC). Our aims were to examine KiSS-1 expression in OSCC tissue samples and cell lines and to determine its prognostic significance. KiSS-1 expression was significantly lower in lymph node (LN) metastases than in primary tumor tissues. Five of six OSCC cell lines showed absence or relatively low expression of KiSS-1. Correlations between KiSS-1 expression and clinicopathological parameters were statistically assessed. There were significant correlations between KiSS-1 expression and LN metastasis (p = 0.007), TNM stage (p = 0.024), and local recurrence (p = 0.012). In the Kaplan-Meier survival analysis, negative KiSS-1 expression significantly correlated with poorer overall survival (OS) and disease-free survival (DFS) (p = 0.000 and 0.000, respectively). Multivariate analysis using Cox regression modeling revealed that KiSS-1 expression was an independent prognostic factor for both OS and DFS (p = 0.001 and 0.000, respectively). Our findings suggested that KiSS-1 downregulation may play a role in tumor progression and metastasis of OSCC and may be a reliable biomarker for predicting clinical outcome in OSCC.