Predictivity of Human Telomerase Reverse Transcriptase (h-TERT) in Oral Squamous Cell Carcinoma: Immunohistochemical Study

Aims: Determine the potential role of h-TERT as a prognostic marker for oral squamous cell carcinoma by evaluating its immunohistochemical expression in different OSCC histologic grades in comparison with normal oral mucosa. Study Design: A retrospective study. Place and Duration: Oncology Center, Mansoura University, and Oral Pathology Department, Faculty of Dentistry, Mansoura University. The worked sample selected from the years (2015-2019). Methodology: Our study was accomplished on 30 OSCC cases and a control group of normal oral mucosa. Histopathologic grading of OSCCs was made using the WHO grade and Anneroth`s grading systems. Immunohistochemical expression of h-TERT was assessed in relation to different clinicopathological parameters. The data was analyzed using Pearson`s chi-square test to compare the differences between groups. Spearman's correlation co-efficiency test was used to test the association between different variables. A P value ≤ 0.05 was considered to be statistically significant. Results: A significant increased h-TERT expression was recorded from normal to OSCC groups (P=0.000). Additionally, elevated h-TERT expression was significantly correlated with the higher carcinoma histologic grade (P =0.025). There were high statistically significant differences in h-TERT expression concerning the parameters; Anneroth pattern of invasion (P= 0.049), depth of invasion (DOI, P=0.024), and lymphoplasmacytic infiltration (LPI, P=0.009). There were no statistically significant differences in h-TERT immunoexpression considering the clinical parameters; patient age, gender, anatomical sites, clinical shape of lesion, T, N, M, and TNM stages (Chi-square test, P values were > 0.05). Conclusions: Increased h-TERT immunoexpression from normal to OSCC groups suggests its involvement in malignant transformation. Additionally, the significant differential expression of h-TERT among different OSCC histologic grades signaling its valuable use as a biomarker for assessing the cellular malignant progression of oral carcinomas, but unreliable as a clinical tumor progression marker. Moreover, the significant correlation of h-TERT expression with LPI, DOI and pattern of invasion indicating its possible reliable role in tumor host relation during multistage carcinogenesis.