Molecular Analysis as a Guide to Determining the Extent and Pathophysiology of Perilesional Tissues in Oral Epithelial Dysplasias.

INTRODUCTION: Clinically and histologically normal appearing perilesional mucosa of epithelial dysplasia may harbor early genetic changes. Hence, the present study is designed to determine the early molecular changes in the form of p16 and EGFR immunoexpressions in perilesional tissues.
OBJECTIVES: To analyze immunohistochemical expressions of p16 and EGFR individually and percentage change of immunoexpressions in oral dysplastic lesions and their perilesional tissues.
MATERIALS AND METHODS: Forty formalin-fixed paraffin-embedded tissues of oral epithelial dysplasia with perilesional tissue marked by India ink were included in this study. Immunohistochemical staining was performed using anti-p16 and anti-EGFR monoclonal antibodies (BioGenex) using squamous cell carcinoma of uterine cervix and breast carcinoma as the positive controls, respectively.
RESULTS: p16 and EGFR expressions were assessed based on the presence, intensity, extent and immunolocalization of positive cells. Out of 40 cases, p16 immunoexpression was positive in 82.5% cases of lesional tissues and in 62.5% cases of perilesional tissues (p ≤ 0.05); however, EGFR immunoexpression was positive in 90% cases of both lesional and perilesional tissues (p > 0.05).
CONCLUSION: The disease status and progression based on p16 and EGFR expressions and co-expressions can be used as an effective guide to evaluating the progression of normal epithelium to dysplastic epithelium in otherwise clinically normal mucosa. © The Association of Oral and Maxillofacial Surgeons of India 2019.