Estimation of serum sialic acid in oral submucous fibrosis and oral squamous cell carcinoma

BACKGROUND AND OBJECTIVES: Sialic acid (SA) N-acetyl neuraminic acid is a negatively charged 9-carbon monosaccharide, commonly attached to the nonreducing residues of carbohydrate chains of glycoconjugates by glycosidic linkage. SA is widely distributed in glycoproteins (GPs) of cell membrane. The alterations in GPs start at an early stage of tumorigenesis. Hence, the aim of the present study is to evaluate the levels of serum SA in normal individuals, in patients with oral submucous fibrosis (OSMF), oral squamous cell carcinoma (OSCC), and compare the levels with respect to the clinical staging and histological grading. MATERIALS AND METHODS: A total of 90 individuals were selected for the purpose of the study. Thirty cases of clinically diagnosed and histopathologically confirmed cases of OSMF and OSCC each were included. A control group of 30 age and gender-matched individuals with no systemic diseases were selected. Serum levels of SA were measured based on the reaction between SA and ninhydrin. The absorbance was read using a spectrophotometer. RESULTS: Serum SA levels were significantly increased in OSMF, OSCC patients as compared with controls. When multiple comparison was done using post hoc Tukey test, there is a statistically significant difference between clinical staging and histopathological grading of OSMF and OSCC (P < 0.05). CONCLUSION: The serum SA levels in OSMF and OSCC patients were increased as compared with controls suggesting that, it can be used as a reliable biomarker for prognostic evaluation, and also give a clue about the amount of tumor burden in the individual.