Expression of human epidermal growth factor receptor 2/Neu in oral leukoplakia

Background: Molecular alterations in premalignant lesions of the oral cavity are not well known. Many reports have found increased human epidermal growth factor receptor 2 (HER-2) expression in oral cancer. Overexpression of HER-2 in premalignant lesions may denote its positive contribution in the malignant transformation of these lesions. Materials and Methods: Twenty-three samples of leukoplakia were stained by routine H and E to assess any dysplasia; five samples of normal mucosa were used as control. Immunohistochemical staining for HER-2 was done. ASCO/CAP 2018 guidelines were used for reporting the results. The percentage of lesions expressing cytoplasmic or membranous expression was calculated. Results: One sample of leukoplakia with severe dysplasia expressed focal membranous staining. Cytoplasmic staining was observed in 3/9 (33.33%) dysplastic leukoplakia. Only one nondysplastic leukoplakia expressed cytoplasmic HER-2 staining. Conclusions: Membranous expression in severe dysplasia and higher expression in oral cancer are in concordance with the multistep theory of carcinogenesis.