High sex determining region Y-box 2 expression is a negative predictor of occult lymph node metastasis in early squamous cell carcinomas of the oral cavity.

BACKGROUND The transcription factor sex determining region Y (SRY)-box 2 (SOX2) (3q26.3-q27) has been recently identified as a recurrently activated major oncogene in squamous cell carcinoma of various sites. Its prognostic value in head and neck squamous cell carcinoma (HNSCC) is currently unclear. AIM To correlate SOX2 protein expression with the occurrence of occult lymph node metastasis and relapse free survival in early oral SCC. METHODS SOX2 expression in 120 T1/T2 oral SCC patients was evaluated using a tissue microarray technique. Intensity of SOX2 expression was quantified by assessing the Intensity/Reactivity Scores (IRSs). These scores were correlated with the lymph node status of biopsied sentinel lymph nodes and recurrence. Log rank univariate and Cox regression multivariate analysis was used to determine statistical significance. RESULTS Twenty-six of 120 primary tumours (21.7%) showed high SOX2 expression. High expression levels of SOX2 significantly correlated with negative lymph node status in univariate (p=0.001) and multivariate analysis (p=0.003). Sensitivity was found to be 95.6% with a negative predictive value of 92.3%. Specificity was 32% with a positive predictive value of 45.7%. CONCLUSION SOX2 up-regulation is frequent in early SCC of the oral cavity and associated with decreased risk of lymphatic metastasis. SOX2 immunohistochemistry may be used as a predictor for lymph node metastasis in squamous cell carcinoma of the oral cavity.