Abstract: Objective To explore the clinical significance of EGFR expression and amplification in tongue squamous cell carcinoma. Methods Detection of EGFR using immunohistochemistry and FISH was conducted in 34 cases of tongue squamous cell carcinoma and their adjacent tissues, along with one case of pseudoepitheliomatous hyperplasia of the tongue in tissue chips. Results The expression and amplification rates of EGFR in tongue squamous cell carcinoma were higher than those in adjacent normal tissues. Specifically, the expression rate of EGFR in cancer tissues was 63. 6 % (21 out of 33 samples), while in normal tissues, it was 0 % (0 out of 33 samples). Regarding amplification, the rate in cancer tissues was 5. 9 % (2 out of 33 samples), whereas it remained at 0 % (0 out of 33 samples) in normal tissues. EGFR expression was not associated with age, gender, tissue grading, or clinical stage, but it was associated with lymph node metastasis. Conclusion: Detection of EGFR is important for differentiating tongue squamous cell
carcinoma in clinical pathology. The overexpression of EGFR protein is partially due to an increase in copy number, and an elevated level of EGFR indicates a poor clinical prognosis.

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