Comparative evaluation of level of serum & salivary lactate dehydrogenase enzyme as a biomarker in oral potentially malignant disorders and oral squamous cell carcinoma

Aim: Lactate dehydrogenase (LDH) is an ubiquitously present enzyme which acts as a catalyst in production of lactate via pyruvate reduction during anaerobic glycolysis. An increase in serum LDH enzymatic activity is used as a biomarker for diagnosis of various types of cancers.This study aims to compare levels of serum and salivary Lactate Dehydrogenase (LDH) enzyme as a biomarker in oral potentially malignant disorders (OPMDs) and Oral Squamous Cell carcinoma (OSCC).
Materials & Methods: A total of 150 subjects of 20 to 70 years were selected from Jharkhand province, divided in five groups, 30 patients each who were clinically and histopathologically diagnosed with Oral Leukoplakia, Oral Lichen planus, Oral Sub mucous Fibrosis (OSMF), Oral squamous cell carcinoma (OSCC) and the control group. Both their salivary& serum samples were collected. Both types of samples were subjected for biochemical analytical tests. The data obtained was analyzed using the statistical software- SPSS version 22.0. Analysis of Variance (ANOVA) and Tukey’s Post Hoc analysis was for inter-group comparison. Pearson’s correlation analysis was used for correlating salivary and serum LDH levels. A statistical difference of P value of 0.05 or less was considered as statistically significant.
Results: Pearson’s correlation test showed statistical significance in various studied groups for both salivary and serum LDH levels. In OSMF subjects, both the salivary and serum LDH levels were exhibiting statistical significance of 0.02 and 0.03, respectively. Similarly in leukoplakia patients, extremely significant P values of 0.01 and 0.02 were observed in both salivary and serum LDH values, respectively. However, in oral lichen planus, no statistical significance was observed in both the salivary and serum LDH levels.
Conclusion: The salivary and serum Lactate Dehydrogenase levels was highest in the patients with Oral Squamous Cell Carcinoma, followed by Oral Leukoplakia, Oral Submucous Fibrosis and oral lichen planus, However, oral lichen planus demonstrated lowest value of both salivary and serum lactate dehydrogenase levels thus, indicating lowest potential towards malignancy.
Clinical Significance: saliva samples can be equally effective in analysis of biochemical markers such as lactate dehydrogenase. Its non-invasive nature is an advantage over serum use for analytical purposes.