Evaluation of salivary tumor necrosis factor α as a diagnostic biomarker in oral submucosal fibrosis and squamous cell carcinoma of the oral cavity and oropharynx: a cross sectional observational study

Abstract

Introduction: Tumor necrosis factor α (TNF-α) is known to be associated with chronic inflammation, and its expression has been shown to increase in advanced cancers. Chronic inflammation is a characteristic feature of oral submucous fibrosis (OSMF), which is a potentially malignant disorder (PMD). Squamous cell carcinoma (SCC) is associated with considerable mortality and morbidity and an early detection or monitoring would greatly help in achieving an effective cure. TNF-α was thus evaluated for use as a biomarker in the present study according to the stage of OSMF and histological grade of SCC in the oral cavity and oropharynx.

Methods: This study included 45 patients divided into 3 groups-OSMF group, SCC group and control group-each comprising 15 participants. Saliva samples were collected from each patient, and salivary TNF-α levels were estimated using an ELISA kit.

Results: Statistical analysis revealed no significant differences in TNF-α levels among the OSMF, SCC and control groups; however, there was an increase in the salivary TNF-α level in patients with stage 3 disease according to the clinical stage of OSMF, for which the p value was 0.027.

Discussion: An increase in the TNF-α concentration with increasing clinical stage suggested a role for TNF-α in the spread of OSMF involvement in anatomical structures of the oral cavity and oropharynx. No significant difference in salivary TNF-α levels was noted among the OSMF, SCC and control groups.

Conclusion: The study showed a positive correlation of TNF-α with increasing stages of OSMF but was not a reliable biomarker in the categorization of the same.

Keywords: TNF-α; biomarkers; oral cavity; oral submucous fibrosis; oropharynx; squamous cell carcinoma.

Figure 1

(A) Cooling centrifuge used for centrifugation of saliva samples, (B–D) reagents used for performing ELISA test, (E) showing addition of reagents (A,B) to the wells, (F) showing addition of stop solution with color change from blue to yellow in sample wells, (G)-LISAPlus microplate reader used for calculating the TNF-α.

Figure 2

(A,B) Pie charts showing distribution of involvement in OSMF group by clinical staging and functional staging, (C) pie chart showing distribution of histological grading among SCC group, (D) box plot showing the TNF-α values between controls, OSMF and SCC. One outlier value of 2,807 has been eliminated from control group to make the graph better.