Overexpression of Id-1 is associated with tumor angiogenesis and poor clinical outcome in oral squamous cell carcinoma

We analyzed the expression of Id-1 in oral squamous cell carcinoma (OSCC) immunohistochemically, and investigated the association of Id-1 expression with tumor angiogenesis and clinical prognosis. Overexpression of Id-1 protein was found in 83 out of 128 cases (64.8%). The expression of Id-1 was significantly associated with tumor size (p = 0.013), lymph node metastasis (p = 0.001), tumor stage (p = 0.031) and tumor recurrence (p = 0.003). Moreover, Id-1 expression was significantly correlated with intratumoral microvessel density (MVD) (r = 0.223, p = 0.011). The results suggest that overexpression of Id-1 was correlated with tumor angiogenesis and poor clinical outcome.