Expression of HER2/neu in premalignant lesions of oral cavity

ContextMolecular alterations in premalignant lesions of oral cavity are not well known, many reports and have found increased HER2 expression to be correlated with poor prognosis in oral cancer. However, literature on expression of HER2 in premalignant lesions is limited and data is conflicting in nature. Overexpression of HER2 in premalignant lesions may denote its positive contribution in malignant transformation of these lesions. AimsTo evaluate the expression of HER2 in premalignant lesions of oral cavity. Settings and DesignIn this prospective observational study of 2 months, patients attending OPD at Department of ENT and meeting the inclusion criteria were included. Methods and Material23 samples of Leukoplakia and 1 sample of oral lichen planus were stained by routine H&E to confirm clinical diagnosis and assess dysplasia if any, 5 samples of normal mucosa were used as control. Immunohistochemical staining for HER2 was done. ASCO/CAP 2018 guidelines were used for reporting the results. Statistical analysis usedPercentage of lesions expressing cytoplasmic or membranous expression was calculated. Results1 sample of Leukoplakia with severe dysplasia expressed focal membranous staining. 20% leukoplakia lesions expressed cytoplasmic staining. Staining was not observed in oral lichen planus and leucoplakia without dysplasia. ConclusionsMembranous expression in Severe dysplasia and higher expression in oral cancer is in concordance with the multistep theory of carcinogenesis. Larger studies are needed if HER2 is to be proposed as a marker for oral premalignant lesions. Significance of cytoplasmic staining in oral premalignant lesions needs to be elucidated. Key MessagesTo the best of our knowledge, this is the first report of focal membranous expression of HER2 in leucoplakia in India. 20% leucoplakia with dysplasia expressed cytoplasmic staining. The significance of cytoplasmic staining needs to be further explored.