Epidermal Growth Factor Receptor (EGFR) membranous and cytoplasmic overexpression on immunohistochemistry: An additional prognostic marker in oral squamous cell carcinoma

ABSTRACT Background: Oral carcinoma is one of the most frequently occurring cancers among Indian men. We conducted this study to find out any association between epidermal growth factor receptor (EGFR) overexpression by immunohistochemical methods with histopathological prognostic parameters like pathological tumor (pT) staging, tumor grade, lymph nodal involvement, extranodal extension (ENE), perineural invasion (PNI), lymphovascular invasion (LVI), and worst pattern of invasion (WPOI). Materials and Methods: This prospective cross-sectional study was conducted in Pathology Department of our institute between December 2021 and November 2022, and a total of 113 confirmed cases of oral squamous cell carcinoma (OSCC) were included in our study. Clinicopathological parameters were recorded, and EGFR expression by immunohistochemistry was evaluated in these patients. The association of EGFR overexpression and the different histopathological parameters according to the College of American Pathologists (CAP) protocol was determined. Results: Out of 113 cases, 52 cases (46%) were positive for EGFR overexpression on immunohistochemistry. Significant association of EGFR overexpression was noted with pT stage, nodal status N0 versus N1–N2, ENE, PNI, LVI, and WPOI, with P value <0.05. No significant association was noted with tumor grade and nodal status N0–N1 versus N2–N3. Conclusion: EGFR overexpression can be used as a prognostic marker in addition to histopathological parameters. One can opt for wedge resection in place of extensive surgery if small punch biopsies show EGFR negativity and radiology shows uninvolved lymph nodes. In addition, in EGFR-positive OSCC cases, targeted therapy could be opted to avoid chemotherapy-related toxicity and increase patient survival.