Salivary lactate dehydrogenase as a biomarker for squamous cell carcinoma

Oral cancer presents challenging and unresolved problems for the human population, and for a high‑risk region like India it is of prime concern. Considering the ever increasing incidence of oral carcinoma in India and worldwide, there is always a need to find out and standardize easier methods for screening, diagnostic as well as therapeutic purposes. In this view, the biochemical studies could prove to be promising in the future. Biochemical studies in the evaluation of cancers have shown that various substances alter quantitatively in the serum during tumor development. The enzyme LDH is found in the cells of almost all body tissues. It is especially concentrated in the heart, liver, red blood cells, kidneys, muscles, brain, and lungs. Increased serum LDH activity is considered as a marker of cellular necrosis, and serum LDH levels have been used as a biochemical marker in the diagnosis of various cancers such as oral, laryngeal and breast cancer. LDH activity is mainly due to genomic changes during malignant transformation. Increased LDH levels are due to increased mitotic index and more lactic acid production by tumor cells due to breakdown of glycoprotein.