Oxidative stress and antioxidant imbalance in endometrial carcinogenesis

To assess dynamic thiol-disulfide homeostasis as a biomarker of oxidative stress in patients with endometrial cancer and to evaluate its association with tumor grade and stage.

This prospective case-control study included 35 patients with histopathologically-confirmed endometrial cancer and 36 age-matched healthy controls. Venous blood samples were obtained after overnight fasting. Serum thiol-disulfide homeostasis parameters were measured using a fully-automated spectrophotometric method. Native thiol, total thiol, disulfide concentrations, and related ratios were analyzed. Tumor grade and International Federation of Gynecology and Obstetrics stage were recorded for all patients.

Native thiol and total thiol levels were significantly lower in patients with endometrial cancer compared with healthy controls (both P < 0.001). Patients with grade 2 tumors exhibited significantly reduced native and total thiol levels compared with grade 1 patients and controls (P < 0.001). A significant inverse correlation was observed between tumor stage and thiol levels, with lower native and total thiol concentrations in stage IB compared with stage IA disease (R = -0.586, and R = -0.604, resp.; P < 0.001). Disulfide levels and thiol-disulfide ratios did not differ significantly between groups.

Dynamic thiol-disulfide homeostasis is markedly impaired in endometrial cancer and is associated with tumor grade and stage. Reduced thiol levels reflect increased oxidative stress and diminished antioxidant capacity, suggesting that thiol-based redox parameters may serve as complementary biomarkers for disease severity and progression in endometrial cancer.