Objective: The objective of this study was to investigate the levels of salivary SIRT-1 and CD44 in patients suffering from oral squamous cell carcinoma (OSCC), dysplastic and non-dysplastic oral leukoplakia to assess their potential role as early diagnostic biomarkers for patients with oral leukoplakia and OSCC.

Subjects and Methods: sixty patients were recruited from the outpatient clinic of the Department of Oral Medicine and Periodontology, Faculty of Dentistry, Cairo University. Participants were divided into four groups:15 healthy individuals, 15 patients with non-dysplastic leukoplakia, 15 patients with dysplastic leukoplakia, and 15 patients with oral squamous cell carcinoma. Whole unstimulated saliva (WUS) was collected from all participants. Soluble CD44 (solCD44) and SIRT1 were measured using ELISA.

Results: CD44 was expressed in all the four study groups with different levels. OSCC showed a statistically significant highest CD44 level. While the control group showed the lowest CD44 level. There was no statistically significant difference between dysplastic leukoplakia and non-dysplastic leukoplakia groups. Similarly, there was no statistically significant difference between non-dysplastic leukoplakia and control groups. OSCC showed the statistically significantly highest SIRT-1 level. There was no statistically significant difference between dysplastic leukoplakia, non-dysplastic leukoplakia, and control groups; all showed statistically significantly lower SIRT-1 levels than the OSCC group.

Conclusion: salivary SIRT-1 and CD44 could be used as a screening tool to improve early detection and diagnostic precision of oral leukoplakia and OSCC.