Overexpression of EGFR in Oral Premalignant Lesions and OSCC and Its Impact on Survival and Recurrence

Abstract

Introduction: Oral squamous cell carcinoma (OSCC) the sixth leading cancer worldwide ranks as the most common cancer in males, and the third most common in females in Pakistan. It is influenced by risk factors which are widely consumed in our population. The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor that is imperative for cell signalling, growth and differentiation. It is mutated and overexpressed in a variety of cancers, while in OSCC it has been linked to poor patient survival; premalignant to malignant transformation and recurrence. This study investigates the use of EGFR as a prognostic factor for OSCC. Materials and Methods: Premalignant (n=29) and OSCC (n=100) formalin-fixed paraffin-embedded tissues were retrieved from the surgical archives of Aga Khan University Hospital (AKUH). Immunohistochemistry for EGFR overexpression was performed using monoclonal antibody on both groups. EGFR expression was correlated with habits of risk factor consumption, clinicopathologic features and 5-year survival and recurrence. Results: 15/29 premalignant and 67/100 OSCC patients had overexpressed EGFR. The upper/lower lip had the highest EGFR positivity among all premalignant sites of lesion (p=0.041). In OSCC patients, those who had EGFR overexpression had worse 5-year survival (univariate: p=0.048, multivariate: p=0.056) and higher chances of recurrence (univariate: p=0.01, multivariate: p=0.004) as compared to EGFR negative patients. Conclusion: EGFR is a viable candidate for an OSCC prognostic marker since its overexpression leads to poor survival and markedly increases the chances of recurrence.