Expression of the proto-oncogene eIF4E in inflammation of the oral cavity.

Abstract

eIF4E (4E) is elevated in 100% of head and neck squamous cell carcinoma (HNSCC) and in premalignant lesions of the larynx. However, it is not elevated in normal mucosa. In this study, we hypothesize that 4E is not significantly elevated in inflammation unlike its expression in premalignant lesions of the oral cavity. Biopsies from the oral cavity were divided into 5 groups: (1) normal mucosa, (2) chronic inflammation, (3) mild dysplasia from leukoplakic lesions, (4) mild dysplasia in surgical margins of patients with HNSCC, and (5) HNSCC. Immunohistochemical qualitative analysis was then performed. None of the 15 specimens in group 1 and 100% of the 15 specimens in group 5 expressed 4E. Of the 29 specimens in group 2 only 4/29 (13%) overexpressed 4E compared with 10/31 (32%) in group 3 and 9/21 (42%) in group 4. There was a significant difference between groups 2 and 3 and groups 2 and 4 (P < 0.0001 and P < 0.003 respectively) but no significant difference between groups 1 and 2 (P = 0.13) and between groups 3 and 4 (P = 0.30). 4E is not significantly elevated in inflammation of the oral cavity thus fulfilling one of the criteria that biomarkers require to be useful in a clinical setting.