Evaluation of Serum and Salivary Pyruvic Acid Levels in Subjects with Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma: A Cross-Sectional Study

Background: Pyruvic acid is considered a prognostic marker of oral squamous cell carcinoma (OSCC) in both serum and saliva. However, few studies have assessed the role of pyruvic acid levels in serum and saliva in oral potentially malignant disorders (OPMDs) and OSCC, or established a correlation between serum and salivary levels. Aim: The cross-sectional study was carried out to assess serum and salivary levels of pyruvic acid as a probable marker for OPMD and OSCC. Methods: Pyruvic acid levels in serum and saliva were evaluated using a colorimetric assay among 25 healthy subjects (Group I), 25 subjects with clinically diagnosed OPMDs (Group II), and 25 subjects with clinically and histopathologically diagnosed OSCC (Group III). Results: The mean pyruvic acid levels in serum were highest in Group II (1.29 ± 0.3 µmol/L), followed by Group III (1.24 ± 0.98 µmol/L) and Group I (0.55 ± 0.3 µmol/L), and the values were statistically significant ( P = 0.022). In saliva, no significant variation was noted in pyruvic acid levels among the three groups ( P = 0.22). The mean difference in serum and salivary pyruvic acid levels among participants in different clinical stages was not statistically significant ( P = 0.108 and 0.22, respectively). However, the mean difference in serum levels was statistically significant with the histopathological grading of OSCC, that is, poorly, moderately, and well-differentiated cases ( P = 0.032), whereas no statistical significance was noted in the salivary pyruvic acid levels ( P = 0.32). Conclusion: This study demonstrated the importance of pyruvic acid in the tumorigenesis process, as elevated serum levels were observed with OPMDs, OSCC, and with clinical stages and histopathological grading of OSCC. As no significance was noted with the salivary levels of pyruvic acid, oral cavity factors like the presence of oral bacteria, pH, and the acidic environment may affect these levels.