High levels of oxidative stress in patients with advanced lung cancer

Background and objective: The aim of this study was to investigate oxidative stress status in different stages and histological types of lung cancer. Methods: Forty-nine lung cancer patients, who had not received any therapy, and 20 healthy subjects were chosen for the study. Lung cancer patients were divided into those with early stage or advanced stage disease. The tumour type was adenocarcinoma in 24 patients, squamous cell carcinoma in 21 and large cell carcinoma in four. We measured serum nitrite, nitrate, ascorbic acid, retinol, beta-carotene and ceruloplasmin levels, and whole-blood malondialdehyde, reduced glutathione levels and catalase activity in patients with non-small cell lung carcinoma and healthy subjects. Results: Statistically significant differences between the patient group and the control group were detected for all biochemical parameters. Mean malondialdehyde, nitrite, nitrate and ceruloplasmin levels and catalase activity were significantly higher in the group with advanced stage disease than in the control group. Mean beta-carotene, ascorbic acid and reduced glutathione levels were significantly lower in the group with advanced stage disease than in the control group. Mean malondialdehyde and nitrite levels were significantly higher in the patients with squamous cell carcinoma than in those with adenocarcinoma, and mean malondialdehyde level was also significantly higher in patients with squamous cell carcinoma than in those with large cell carcinoma. Conclusions: These results suggest that with advancing stage of lung cancer, the levels of oxidative stress increase, while levels of antioxidant molecules decrease. Patients with squamous cell carcinoma have higher oxidative stress as reflected by higher levels of malondialdehyde and nitrite.