Evaluation of the Immunohistochemical Expression of Lipid Peroxidation Marker 4-HNE and Comparison of the Expression in Various Histopathological Grades of Oral Squamous Cell Carcinoma

Abstract

Objective: This retrospective immunohistochemical study evaluated the expression of 4-hydroxy-nonenal (4-HNE), a marker of lipid peroxidation, in oral squamous cell carcinoma (OSCC) and compared staining intensities across different histopathological grades.

Materials and methods: Archived formalin-fixed, paraffin-embedded tissue blocks from 55 primary OSCC patients were analyzed. Normal oral mucosa samples (n = 10) served as controls. Immunohistochemical staining intensity for 4-HNE was semi-quantitatively assessed. Data were analyzed using SPSS version 20.0. The Chi-square test compared 4-HNE expression between normal and OSCC tissues, while the Kruskal-Wallis H test assessed differences among OSCC grades. A p-value <0.05 was considered statistically significant.

Results: In normal tissues, 90% showed no staining, and 10% exhibited mild staining (median score = 0). OSCC samples displayed moderate staining in 34.5% and intense staining in 65.5% (median score = 3). Among histological grades, well-differentiated tumours showed 40% moderate and 60% intense staining; moderately differentiated, 30% moderate and 70% intense; poorly differentiated, 33.3% moderate and 66.7% intense. Expression of 4-HNE was significantly higher in OSCC compared to controls (p < 0.001) but did not differ significantly among OSCC grades.

Conclusion: Elevated 4-HNE levels in OSCC suggest enhanced oxidative stress and lipid peroxidation, supporting its potential as a biomarker in carcinogenesis.

Keywords: Immunohistochemistry; lipid peroxidation marker; oral Cancer.