Correlations Between Metformin and Prognosis and Adverse Reactions in Patients Undergoing Radical Cystectomy Followed by Adjuvant GC Chemotherapy for Bladder Cancer

Objective The objective of this research was to examine the influence of metformin on both prognosis and adverse reactions in patients who have undergone radical cystectomy (RC) and subsequently received adjuvant gemcitabine and cisplatin (GC) chemotherapy for muscle-invasive bladder cancer (MIBC). Methods A retrospective evaluation was performed on data from 243 patients who had undergone RC followed by adjuvant GC chemotherapy at the Affiliated Hospital of Xuzhou Medical University, Xuzhou First People’s Hospital, and Xuzhou Third People’s Hospital during the period from April 2014 to April 2024. The subjects were categorized into three categories based on metformin usage: non-diabetic (No DM), type 2 diabetic with metformin use (DM, Metformin), and type 2 diabetic without metformin use (DM, no Metformin). Clinical and pathological characteristics were compiled and subjected to analysis. Progression-free survival (PFS) was assessed utilizing the Kaplan-Meier technique, while Cox proportional hazards models were employed for multivariable analysis. Results Among the 243 patients, diabetes was present in 68 individuals, of whom 51 were administered metformin. When compared to the non-diabetic cohort, diabetic patients who received metformin exhibited significantly elevated PFS rates at 1, 2, and 3 years ( p  = 0.024). Both univariate and multivariate analyses indicated that the utilization of metformin correlated with a reduced risk of disease progression (hazard ratio = 0.66, 95% confidence interval 0.45–0.96, p  = 0.031). Moreover, those administered metformin experienced a significantly lower frequency of grade 3 or higher adverse reactions during chemotherapy in contrast to those who did not receive metformin ( p  = 0.011). Conclusion The administration of metformin is strongly correlated with enhanced prognosis and a reduction in adverse reactions in patients who have undergone RC, followed by adjuvant GC chemotherapy for MIBC. This research offers robust clinical evidence supporting the application of metformin as an adjuvant therapy in MIBC and establishes a basis for future investigations into the mechanisms by which metformin exerts its effects in cancer treatment.