S100A7 as a predictive biomarker in malignant transformation of oral epithelial dysplastic lesions.

Abstract

Background: S100A7 expression is increased in oral epithelial dysplasias at risk of transformation to oral squamous cell carcinoma (OSCC). The objective of this study was to evaluate S100A7 expression in dysplastic lesions which transformed and to correlate these results with the 3-tier and 2-tier dysplasia grading systems, and an S100A7 immunohistochemistry-based signature algorithm (S100A7 ARS). Methods: Formalin fixed paraffin embedded specimens from 48 patients with dysplastic lesions that had transformed into OSCC were selected. Thirty-five patients with multiple biopsies of dysplasia which had not transformed, and 25 cases with normal appearing and/or hyperkeratotic oral mucosa were included as control groups. Specimens were stained for S100A7 protein by immunohistochemical methods. Expression of S100A7 was assessed semi-quantitatively and by image analysis for the S100A7 ARS. Results: The semi-quantitative score had strong correlation with the S100A7 ARS and allowed differentiation of dysplastic lesions from the Control groups. The S100A7ARS was also useful in differentiation of dysplasias that transformed to carcinoma from non-transforming cases (p < 0.05). Conclusion: S100A7 immunohistochemical staining and the S100A7 ARS has potential for identifying oral potentially malignant lesions that have an increased risk of malignant transformation.