Thiol/Disulfide Homeostasis in Lung Cancer: Insights from a Clinical Study

Background: The development of lung cancer is strongly influenced by oxidative stress (OS), which results when the balance between oxidants and antioxidants is disturbed. Evaluation of both specific redox markers such as thiol/disulfide homeostasis (TDH) and overall indicators including total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) may provide a more comprehensive view of oxidative imbalance in lung cancer. We examined OS indices and TDH in patients with lung cancer versus healthy controls. Methods: Eighty participants were enrolled, consisting of 40 patients with newly diagnosed lung cancer and 40 age- and sex-matched healthy controls. Serum levels of native thiol (NT), total thiol (TT), and disulfide were determined using an automated spectrophotometric method. Additionally, TAS, TOS, and the OSI were evaluated to provide an overall assessment of oxidative balance. Routine hematological and biochemical parameters were compared between groups. Results: White blood cell and neutrophil counts were notably higher in lung cancer patients compared with controls (p < 0.05). NT and TT levels were remarkably decreased, whereas disulfide levels, TOS, and OSI were significantly elevated in the lung cancer group (p < 0.05). TAS levels tended to be lower in patients, although not reaching statistical significance. No significant association was observed between oxidative parameters and tumor stage or localization. Conclusions: Patients with lung cancer exhibited a marked oxidative imbalance, characterized by elevated oxidant burden and impaired TDH. Combined assessment of TAS, TOS, OSI, and thiol/disulfide parameters may provide valuable insight into the oxidative pathophysiology of lung cancer and hold potential as complementary biomarkers for disease evaluation. Further large scale studies are needed to confirm these findings.