Objectives: Previous studies have demonstrated that microRNA-21 (miR-21) and total antioxidant capacity (TAC) could be potential diagnostic biomarkers for oral squamous cell carcinoma. Their diagnostic potential in the early stages of carcinogenesis is not clear yet. This study was conducted to determine the salivary levels of miR-21 and TAC in patients with oral hyperplasia and dysplasia.
Methods: We assessed expression of miR-21 and TAC in whole unstimulated saliva samples of 30 patients with oral mucosal lesions demonstrating hyperplastic or dysplastic changes and 30 healthy individuals with normal mucosa. Biopsy was taken from the lesions for histopathologic assessment. Statistical analysis was performed with IBM® SPSS® (P ≤ 0.05) and ROC curve analysis was conducted with MedCalc.
Results: miR-21 expression varied among the studied groups with significant difference. However, TAC expression varied only between mucosal lesions and normal mucosa with significant difference. Diagnostic accuracy, sensitivity, specificity, positive predictive value and negative predictive value were higher in miR-21 than TAC.
Conclusions: Salivary miR-21 are more accurate in detecting oral dysplasia than salivary TAC. Salivary miR-21 could be potential diagnostic biomarker for screening and early detection of oral cancer. More studies are required to validate miR-21.