title: Histopathological differentiation of oral squamous cell carcinoma and salivary lactate dehydrogenase: A biochemical study.
abstract: BACKGROUND
  Early diagnosis of oral cancer is a priority health objective, in which oral health professionals may play a pivotal role. Detection should lead to less damage from cancer therapy and to a better prognosis.
  
  
  OBJECTIVE
  The aim was to estimate and compare the salivary lactate dehydrogenase (LDH) levels in various histological differentiation of oral squamous cell carcinoma (OSCC) patients and normal subjects.
  
  
  METHODS
  Hospital-based setting, case-control study.
  
  
  METHODS
  A case-control study was undertaken comprising 30 OSCC patients and 30 healthy controls. The OSCC patients were grouped into well-differentiated, moderately differentiated and poorly differentiated OSCC based on their histological tumor differentiation. Unstimulated whole saliva was collected, assayed for LDH levels using a standard kit and measured spectrophotometrically at 340 nm.
  
  
  METHODS
  The results obtained were subjected to statistical analysis using Kruskal-Wallis and Mann-Whitney U-tests. Spearman's correlation was used to correlate the histological tumor differentiation with the salivary LDH levels.
  
  
  RESULTS
  The mean salivary LDH levels in the control group, well-differentiated OSCC group, moderately differentiated OSCC group, and poorly differentiated OSCC group were 117.33 ± 19.37 IU/L, 355.83 ± 16.73 IU/L, 484.18 ± 25.84 IU/L, and 620.35 ± 18.69 IU/L, respectively. The difference in the mean salivary LDH levels was statistically significant among the various groups (Kruskal-Wallis χ(2) = 50.820, P < 0.001). Spearman's correlation showed significant difference between salivary LDH levels and histological differentiation of OSCC (r = -0.689, P < 0.01).
  
  
  CONCLUSIONS
  The salivary LDH levels were higher in OSCC patients when compared to the healthy controls. The salivary LDH levels were found to be the highest among the poorly differentiated OSCC.
authors.affiliation: Department of Public Health Dentistry, Nitte University, Mangalore, Karnataka, India.
authors.forename: Audrey M
authors.initials: AM
authors.lastname: D'Cruz
authors.affiliation: Intern, A. B. Shetty Memorial Institute of Dental Sciences, Nitte University, Mangalore, Karnataka, India.
authors.forename: Varsha
authors.initials: V
authors.lastname: Pathiyil
keywords: Histopathology; oral cancer; salivary lactate dehydrogenase