Evaluation Of Biomarkers of Oxidative Stress Levels in Chemoradiotherapy Induced Oral Mucositis in Head and Neck Cancer Patients - A Hospital Based Prospective Study

Abstract

Introduction: Oral mucositis is a painful debilitating inflammation and ulceration in the oral mucosa that occurs as the adverse effect of chemoradiotherapy due to release of free radicals. Aim of the study was to evaluate defensive action of Superoxide dismutase (SOD), Glutathione peroxidase (Gpx) and oxidative stress determinant 8-hydroxy 2-deoxyguanosine(8-OHdG) in chemoradiotherapy-induced oral mucositis in HNC patients. Methods: 40 patients undergoing chemoradiotherapy were evaluated for oral mucositis were included in this study. Oral Mucositis progression according to grades on Day 1,7,30 were analysed using Friedman tests. Salivary SOD, Gpx and 8-OHdG levels were assessed using the enzyme-linked immunoassay (ELISA) method. The data were statistically analysed using the ANOVA test to determine the significance of each salivary marker. Level of significance was set at P<0.05RESULTS- Superoxide Dismutase levels are significantly decreased in HNC prior CRT (Day 1) (0.77±0.11 ng/ml), Day 7 (0.63±0.09ng/ml), Day 30 (0.43±0.08 ng/ml) compared to healthy controls (0.99±0.10 ng/ml (P<0.05). Levels of Glutathione peroxidase were significantly reduced in HNC prior CRT (Day 1) (0.64±0.06 ng/ml), Day 7 (0.53±0.03ng/ml), Day 30 (0.45±0.05 ng/ml) compared to healthy controls (0.77±0.04 ng/ml) (P<0.05). 8-hydroxy 2-deoxyguanosine levels were significantly elevated in HNC prior CRT (Day 1) (6.61±0.57 ng/ml), Day 7 (7.90±0.46ng/ml), Day 30 (08.99±0.70 ng/ml) compared to healthy controls (5.33±0.55 ng/ml) (P<0.05). There was statistically significant difference in grading of oral mucositis between Day 1 and Day 30(p<0.01), Day 7 and Day 30(p<0.01). Conclusion: Levels of superoxide dismutase and glutathione peroxidase were reduced representing lack of antioxidant defense and 8-OHdG levels were significantly elevated denoting the increased oxidative stress in patients with oral mucositis undergoing chemoradiotherapy in Head and Neck cancer. Effective antioxidant therapy as a supportive care can prevent the occurrence and severity of oral mucositis in HNC patients.