Correlation of Salivary Lactate Dehydrogenase Levels with Histopathological Grades of Oral Cancer

Background Oral squamous cell carcinoma (OSCC) remains a significant global health challenge with high morbidity and mortality rates. Early detection is crucial for improving prognosis, and noninvasive biomarkers like salivary lactate dehydrogenase (LDH) offer promising diagnostic potential. Methods A cross-sectional study was conducted on 90 participants divided into three groups: 30 patients with well-differentiated OSCC, 30 with moderately/poorly differentiated OSCC, and 30 healthy controls. Unstimulated whole saliva was collected from all participants, and LDH levels were measured using a standardized enzymatic assay. Histopathological grading was performed according to WHO classification. Statistical analysis included ANOVA, post-hoc tests, and Pearson correlation. Results: Salivary LDH levels were significantly elevated in OSCC patients compared to controls (825.4 ± 142.3 U/L vs. 215.7 ± 58.6 U/L, p < 0.001). Furthermore, moderately/poorly differentiated OSCC showed higher LDH levels (986.3 ± 127.8 U/L) compared to well-differentiated OSCC (664.5 ± 98.7 U/L) (p < 0.001). A strong positive correlation was observed between LDH levels and histopathological grades (r = 0.78, p < 0.001). At a cutoff value of 620 U/L, salivary LDH demonstrated 86.7% sensitivity and 93.3% specificity for differentiating OSCC from controls. Conclusion Salivary LDH levels correlate significantly with histopathological grades of OSCC, suggesting its potential as a non-invasive biomarker for assessing tumor aggressiveness and prognosis. This simple, cost-effective biomarker could complement existing diagnostic methods and aid in early detection and management of oral cancer. Bangladesh Journal of Medical Science Vol. 25. Supplementary Issue 2026, Page : S96-S101