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.