Serum and salivary sialic acid as a biomarker in oral potentially malignant disorders and oral cancer.

Background: Aberrant glycosylation is the universal feature of cancer and components of various glycoconjugates, such as sialic acid is found to rise in various malignancies. The objective of this study was to evaluate the serum and salivary sialic acid in oral potentially malignant disorders (OPMD) and oral cancer (OC) to investigate the possibility of using this as a diagnostic marker. Materials and Methods: The study included 85 subjects, who were grouped as control (30), OPMD patients (25), and oral cancer patients (30). Serum and unstimulated whole saliva was collected from subjects of all groups and sialic acid estimation was done using spectrophotometry. The results were tabulated and analyzed statistically. Results: The mean serum sialic acid levels in normal, OPMD, and oral cancer group were 7.515, 19.620, and 55.235 mg/dL, respectively, whereas the levels of salivary sialic acid were 1.5113, 2.3302, and 9.0304 mg/dL, respectively. A very highly significant rise (P < 0.005) in serum and salivary sialic acid was observed in the study subjects compared with that of the control. Conclusions: The present study showed a significant and gradual increase in serum and salivary sialic acid from control to oral potentially malignant disorders to oral cancer. From this study we can suggest that sialic acid can be used as a reliable biomarker. As this monosaccharide is observed in saliva in detectable quantity, saliva can be used as a diagnostic medium for screening and early detection of oral cancer.

Expression of podoplanin in oral premalignant and malignant lesions and its potential as a biomarker.

Aim: To analyze and compare the expression of podoplanin in normal oral tissues, leukoplakia and oral squamous cell carcinoma (OSCC) and to predict its use as a biomarker. Materials and Methods: Ninety‑two formalin fixed paraffin embedded tissue samples comprising of 32 cases of leukoplakia, 50 cases of OSCCs and ten normal gingival samples. The samples were retrieved from archives and immunohistochemically analyzed using podoplanin. Appendix tissue samples were used for control purposes. The results were tabulated and statistically analyzed using ANOVA/Kruskal–Wallis test with post‑hoc tests, where demographic details are compared and analyzed using Pearson Chi‑square test. Results: The study results showed, absence of podoplanin expression in the epithelium of all the gingival samples (Group I). Positive podoplanin expression noticed in 19 out of 32 (59.4%) cases of leukoplakia (Group II) and 41 out of 50 (82%) cases of OSCCs (Group III). The expression of podoplanin among different groups was highly significant (P = 0.000). Conclusion: The podoplanin may be considered as a predictor marker in assessing malignant transformation of premalignancies and prognosis of oral malignancy. Indeed it is believed that podoplanin might play a role in tumor progression though exact mechanism is not fully elucidated. Further research is required to understand its exact pathophysiology.