Oral cancer is one of the highly prevalent cancers worldwide being. According to data of GLOBOCAN 2018, the estimated incidence, mortality and 5-year survival rates due to lip, oral cavity and salivary gland cancer in world is (2.0%), (0.5%) and (0.3%) respectively. (Bray, Ferlay and Soerjomataram, 2018). Endothelin-1 (ET-1) is a 21-amino acid peptide; its receptors have been implicated in the growth and progression of both primary and metastatic neoplasms throughout the human body. Studies have shown that ET-1 is expressed in tissue, serum and other body fluids.

To estimate the levels of salivary endothelin-1 in Oral potentially malignant disorders (oral leukoplakia and submucous fibrosis) and oral squamous cell carcinoma.

The study population included 60 subjects and were divided into 4 groups. All patients included in the study are clinically and histopathological diagnosed cases of oral leukoplakia, submucous fibrosis and oral cancer and assessed for salivary ET-1 levels using human ELISA kit. Significant differences between the groups were determined using one-way analysis of variance, LSD and Post HOC, unpaired t test, biserial and spearson's correlation.

The mean levels of salivary Endothelin-1 level in study groups were: 82.78 ± 5.9 pg/mL (OSCC), 65.02 ± 1.8 pg/mL (SMF), 57.76 ± 4.1 pg/mL (LEUKOPLAKIA), 29.72 ± 14.1 pg/mL (CONTROLS). The mean Salivary ET-1 levels among these four groups was compared and the difference was statistically significant (P < 0.001). We also found a significant difference in the means of ET-1 levels among the clinical and histopathological staging of the study groups.

Our results demonstrate potential utility of salivary analysis for ET-1 levels to monitor patients at risk for OSCC. Although provides the basis for a larger prospective study to determine the critical levels of salivary ET-1 necessary to diagnose and monitor OPMD's and its potential to undergo malignant transformation.