Therapeutic Insights: HER1-Driven Immune Modulation in Pathological Progression and Disease Management of Oral Cavity Carcinomas

Background: Oral cavity carcinoma (OCC) is a virulent malignancy associated with a poor prognosis, typically presenting under immune evasion and further progression. The Human Epidermal Growth Factor Receptor 1 (HER1/EGFR) is involved in the progression of tumors and immune suppression in solid tumors. The objective of this study was to assess the HER1 expression and its correlations with tumor-infiltrating lymphocytes (CD8+, FOXP3+) and immunosuppressive cytokines (IL-6, TGF-beta) in OCC. Methods: This case-control study was conducted between January and June of 2025 at an oncology department. 150 OCC tissue samples were histologically confirmed, and 50 non-malignant controls were analyzed. Immunohistochemistry (IHC) was performed to identify HER1, CD8+, and FOXP3+ markers, whereas IL-6 and TGF-beta were measured by RT-qPCR. Tumors were stratified by HER1 positivity, and statistical tests were conducted using SPSS 26.0. t-Test and chi-square tests were utilized, and the significance level was set at p < 0.05. Results: Its overexpression was observed in 123 (82%) of OCC tumors (p <0.001) and strongly correlated with low CD8+, high FOXP3+, regulatory T cells, and high IL-6 and TGF-b concentrations (p < 0.001). In HER1-positive samples, the strongest immune suppression was observed in the case of advanced-stage tumors. Conclusion: In addition to being a growth-stimulatory oncogene, HER1 plays a central role in immune dysregulation in OCC. The results support HER1-directed treatments as a strategic resource to reverse immune escape and manage OCC patients.