BACKGROUND: Oxidative stress parameters such as total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI) have been studied in breast, thyroid, and simple esophageal cancers (EC). We evaluated these parameters in patients with EC and analyzed their correlations with treatment outcomes.

MATERIAL AND METHODS: Serum TOS, TAS, and OSI in 92 patients with EC at different clinical stages and in 64 healthy people (controls) were measured.

RESULTS: Serum TOS, TAS, and OSI were significantly different between patients with EC and healthy controls (all p<0.001); however, there were no significant differences across different clinical stages (all p>0.05). These factors are not correlated with smoking or drinking history (all p>0.05). Patients with EC with higher TOS and OSI and lower TAS had better responses to chemotherapy and/or radiotherapy, but there was no significant correlation with different responses (all p>0.05). In a receiver operating characteristic curve analysis comparing patients with EC with healthy controls, the Youden indices were 0.391, 0.886, and 1, respectively.

CONCLUSIONS: Serum TOS, TAS, and OSI were significantly different between patients with EC and healthy controls. In patients with EC, these factors were not correlated with smoking or drinking history or with clinical stage. Patients with EC with higher TOS and OSI and lower TAS had a trend towards better outcomes but it did not reach significance. Serum TOS and OSI are potential diagnostic biomarkers that can be used to identify cases of EC.

Keywords: Oxidants