Cytochrome P-450 expression and lipid peroxidation in gallbladder cancer

BACKGROUND AND OBJECTIVES: Carcinoma of the gallbladder is the commonest neoplasm of the biliary tract; however, the etiology of this tumor remains unclear. METHODS: A case-control study was carried out comprising 50 patients with gallbladder cancer and 50 patients with cholelithiasis. Cytochrome P-450 estimation was carried out in the gallbladder tissue, and lipid peroxide product melonaldehyde (MDA) was measured in gallbladder bile. Statistical analysis was carried out by Student's t-test, and one-way analysis of variance (ANOVA). The Pearson correlation coefficient was calculated, and linear regression analysis was performed. RESULTS: The mean cytochrome P-450 concentration was significantly higher in patients with carcinoma of the gallbladder than in controls (t = 3.9, P < 0.001; F = 15.2, P = 0.002). Similarly, the mean concentration of melonaldehyde was significantly higher among cancer patients than in patients with gallstones (t = 2.7, P < 0.003; F = 7.37, P = 0.0078). No significant correlation was observed between tissue MDA and cytochrome P-450 levels (Pearson r = 0.1, P = 0.28). CONCLUSIONS: The results of the present study show that the rise in concentration of MDA is independent of the rise in concentration of cytochrome P-450; however, this is statistically insignificant. This could be due to biliary stasis leading to a rise in biliary concentration of melonaldeyde that is disproportionate to its production.