Altered antioxidant status and lipid peroxidation in Indian patients with urothelial bladder carcinoma☆

Abstract 

Objectives

Urothelial carcinoma of bladder is the second most common urological malignancy after prostate cancer. Recently, there has been increased interest in research of the role of free radicals and antioxidant materials in the prevention, treatment, and alleviation of therapy-related side effects of cancer. In the present study, we aimed to assess the alterations in the levels of antioxidant vitamins, activities of defense enzymes, circulating lipid peroxide, and total antioxidant activity (AOA) in patients with urothelial carcinoma of bladder and correlate these changes with the grade and severity of the disease.

Materials and methods

The study cohort consisted of 90 subjects; 50 patients with bladder UC (25, low grade; 10, high grade; 15, muscle invasive) and 40 healthy controls. Vitamins C and E, malondialdehyde (MDA), and AOA were estimated using standard protocols. Superoxide dismutase (SOD) and glutathione peroxidase (GPx) were assayed using commercially available kits.

Results

The serum levels of vitamins C and E, whole blood levels of SOD and GPx, and serum AOA was significantly lower (P < 0.001) while serum MDA levels were significantly higher (P < 0.001) in patients than in controls, indicating presence of oxidative stress in bladder UC patients. The levels of all the biochemical parameters were correlated with the grade and severity of the disease. There were significant differences between the patients with low grade tumors and muscle invasive tumors for all parameters (P < 0.001); except AOA (P < 0.279).

Conclusions

The observed redox imbalance in UC of bladder in correlation with the grade and stage, as a consequence of decreased levels of antioxidant vitamins, enzymes, and AOA, along with increased MDA levels in circulation, may be important factors in tumor development and growth. Our results suggest that with advancing stage of bladder UC, the levels of oxidative stress increase, while levels of antioxidant molecules decrease. These findings suggest possible use of antioxidant supplementation as prophylactic agents for prevention and treatment of bladder cancer.

Keywords: Oxidative stress, Antioxidants, Urinary bladder cancer, Vitamins, SOD, GPx, MDA