Cyclooxygenase-2 – An Imperative Prognostic Biomarker in Oral Squamous Cell Carcinoma- An Immunohistochemical Study

Oral squamous cell carcinoma (OSCC) is the most common head and neck squamous cell carcinoma (HNSCC) with metastasis and tumor recurrence resulting in 90 % of cancer associated mortality. COX-2, an inflammatory biomarker, has been shown to play a significant role in tumorigenesis of OSCC. To study the expression of COX-2 in OSCC by immunohistochemistry and investigate its association with the clinicopathological parameters including patient survival. A cross sectional study was carried out in 75 histologically confirmed cases of OSCC. COX-2 expression was evaluated by indirect streptavidin biotin method. The expression was semi-quantitatively assessed using established criteria. The expression profile of COX-2 was correlated with the clinicopathological details like tumor size, regional lymphnode metastasis, distant metastasis, clinical stage, local recurrence of tumor, histological grade, and survival of patient. Chi square and Kaplan Meier statistical tests were applied for assessing this association. COX-2 expression was absent in normal oral mucosa. Over expression of COX-2 was seen in 58 out of 75 specimens of OSCC. Overexpression of COX-2 was significantly associated with the lymphnode involvement, histological grade, local recurrence of tumor and patient survival. COX-2 expression represents an important biomarker of prognostic significance that may be used to identify a subset of patients at high risk and to predict patient survival.