Immunohistochemical Expression of EGFR and Her2; and its Correlation with WHO Grades of Head and Neck Squamous Cell Carcinoma
Background: Head and neck squamous cell carcinoma is the seventh most common malignancy in the world. EGFR is over expressed in approximately 80% to 90% of all cases of squamous cell carcinoma of head and neck (HNSCC), whereas HER2 overexpression ranges from 0 to 53%.
OBJECTIVES: To identify the expression of EGFR & HER2 and their correlation with WHO grades in Head and neck squamous cell carcinomas
Materials and Methods: This Cross-sectional comparative study was carried out in Department of Pathology, PIMS, Shaheed Zulfiqar Ali Bhutto Medical University (SZABMU), Islamabad, from December 2017 till November 2018. Mucosal biopsies were processed and stained with Hematoxylin and Eosin (H&E). Slides were examined and histological sub-typing of HNSCC was done. Immunohistochemistry was performed on selected sections to evaluate immuno-expression of EGFR and HER2. Immunohistochemical scoring was done taking into account both staining intensity and percentage of positive cells.
Results: Out of 74 cases, 47 were males and 27 were females. 38 cases were G1 well differentiated, 19 were G2 moderately differentiated and 17 were G3 poorly differentiated SCC. Most frequent site of SCC was oral cavity followed by larynx and pharynx respectively. EGFR was positive in 60 (81.08%) cases and HER2 in 33(44.59%) cases. All HER2-positive cases were also positive for EGFR, except for one poorly differentiated carcinoma.
Conclusion: A statistically significant correlation is seen between IHC immunoexpression of EGFR and HER2. Also, gender shows a clinically significant correlation with anatomical sites of HNSCC. Age groups and anatomical sites are also significantly correlated with the WHO grades of tumor.