Immunohistochemical Expression of E-cadherin in Premalignant and Malignant Squamous Lesions of the Oral Cavity: A Cross-sectional Study

Abstract

Introduction: Squamous Cell Carcinoma (SCC) constitutes 90% of the malignancies of the oral cavity, making it the 6th most common cancer worldwide. Premalignant lesions of the oral cavity carry an increased risk for the development of oral SCC, which is a multistage process. Numerous molecules are involved in this process, and E-cadherin is one of them. E-cadherin is a 120 kDa glycoprotein and a calcium-dependent molecule involved in cell adhesion. Altered expression of E-cadherin has been described in preinvasive lesions and malignancies of the cervix, oesophagus, and head and neck. Aim: The aim of this study was to observe the Immunohistochemical (IHC) expression pattern of E-cadherin in premalignant and malignant lesions of the oral cavity and to correlate E-cadherin immunoexpression between different grades of dysplasia and malignancy. Materials and Methods: This cross-sectional, ambispective study was conducted at Sri Dharmasthala Manjunatheshwara College of Medical Sciences and Hospital, Dharwad, Karnataka, India. The study duration was two and a half years, with one year being retrospective from July 2014 to June 2015, and the remaining period being prospective from July 2015 to December 2016. Systematic random sampling was done to select 60 cases. Premalignant and malignant lesions of the oral squamous epithelium were classified according to the 2017 World Health Organisation (WHO) classification and subjected to E-cadherin immunohistochemistry. Grading of expression was based on the percentage of cells showing continuous homogenous membranous staining: 0 (negative)=0 to 10%, 1+ (loss)=11-25%, 2+ (weak)=26% to 50%, 3+ (strong)=51% to 75%, 4+ (intense)=>75% of cells. Results were analysed using the Statistical Package for Social Sciences version 20.0. Results: The expression of E-cadherin between the different grades of premalignant lesions varied significantly (p-value=0.003), ranging from intense expression in mild dysplasia to weak expression in high grades of dysplasia. Immunoexpression was intense (4+) in 50% of cases, strong (3+) in 39.28%, and weak (2+) in 7.14% of cases. The expression of E-cadherin between the different grades of malignant lesions also varied significantly (p-value=0.002), ranging from negative expression in poorly differentiated SCC to strong expression in well-differentiated SCC. Immunoexpression was negative (0) in 31.25% of cases, strong (3+) in 31.25%, weak (2+) in 15.62%, and (1+) in 21.87% of cases. The pattern of expression was also significant between premalignant and malignant lesions (p-value <0.0001). Conclusion: As the grades of dysplasia and malignancy increase, the expression of E-cadherin reduces. Hence, there is a negative correlation between E-cadherin expression and the grades of dysplasia and malignancy.

Keywords

• e-cadherin
• immunohistochemistry
• oral premalignant and malignant
• pattern of expression