The Effect of Glutathione on Development and Prognosis in Non-Muscle-Invasive Bladder Cancer

Background: Glutathione, along with its related enzymes, constitutes a key antioxidant defense mechanism against oxidative stress and cancer formation in the body. Among urological malignancies, bladder cancer ranks second following prostate cancer. Oxidative stress has significant involvement in the development and prognosis of bladder cancer. This investigation aimed to examine the impact of glutathione on prognosis in patients with non-muscle-invasive bladder cancer. Methods: This study included 98 patients with high grade non-muscle-invasive bladder cancer who had undergone intravesical Bacillus Calmette–Guérin therapy and 30 healthy controls with no history of uroepithelial carcinoma of the bladder. The patients with bladder cancer were evaluated in three subgroups. Group 1 consisted of 41 patients who did not experience recurrence during follow-up, Group 2 included 28 patients who had recurrent tumors, and Group 3 consisted of 29 patients who progressed to muscle-invasive stages. Blood samples were collected from all participants. Blood levels of reduced, oxidized, and total glutathione were measured spectrophotometrically. Results: Reduced glutathione levels significantly differed among the groups (p < 0.001), attributed to the control group exhibiting higher reduced glutathione levels compared with Groups 1, 2, and 3 (p < 0.001). There were no significant differences in reduced glutathione levels between Groups 1 and 2, Groups 1 and 3, or Groups 2 and 3 (p > 0.05). Total glutathione levels varied significantly among the groups (p < 0.001), with the control group having higher levels than Groups 1, 2, and 3 (p < 0.001). No significant differences were detected between any of the paired patient groups in terms of total glutathione levels (p > 0.05). Regarding oxidized glutathione levels, the difference was statistically significant (p < 0.001), with the control group showing lower levels than the remaining three groups (p < 0.001). Paired comparisons revealed no significant differences in oxidized glutathione levels (p > 0.05). Conclusions: This study revealed that glutathione had an effect on the emergence of bladder cancer but did not affect its prognosis. Nevertheless, we recommend that future studies with larger bladder cancer patient cohorts should be conducted to comprehensively determine the impact of glutathione on the prognosis of this cancer.