Salivary Lactate Dehydrogenase (LDH)- A Novel Technique in Oral Cancer Detection and Diagnosis

Oral squamous cell carcinoma (OSCC) is the sixth most common malignancy which is a major cause for cancer morbidity and mortality worldwide. Early diagnosis and intervention improves the overall survival rate.The current study was done to evaluate the accuracy of salivary LDH as a potential biomarker for diagnosis of OSCC and to correlate the levels of salivary LDH with the histological differentiation of the tumour.Thirty patients visiting the outpatient department diagnosed clinically and histologically with OSCC were selected for the study with a control group of 20 patients. Unstimulated salivary samples collected from the selected patients were centrifuged and processed. Readings of enzyme activity in the salivary samples was established through auto analysis using International Federation of Clinical Chemistry (IFCC) method. Levels of the enzyme activity in both the control and the study group were compared and statistically analysed using student t-test. The three subgroups were also compared and statistically analysed.The results showed a mean value of 497.00 with a SD of 51.75 among the control group and a mean value of 1225.40 with a SD of 221.79 among the cases with a p-value of 0.0001 which was statistically significant. Furthermore, when the LDH values for the various grades of OSCC were compared, the mean values were 1049.07, 1309.50 and 1586.20 respectively, for well differentiated, moderately differentiated and poorly differentiated carcinoma.The p-value thus obtained revealed LDH values which were significantly higher in patients with OSCC and furthermore the levels significantly correlated with the histopathological grade of the tumour.