Risk of Bladder Cancer in Patients with Chronic Indwelling Catheters: A Real-World Data Analysis.

<b>Introduction:</b> Bladder cancer is the second most common urological malignancy worldwide, with significant morbidity and mortality. This study investigates the association between chronic indwelling catheter (CIDC) use and bladder cancer risk, particularly in relation to comorbidities and complications. <b>Methods:</b> Taiwan's National Health Insurance Research Database between 2007 and 2018 was used in this study. Patients with CIDC were identified based on records of catheterization on more than six occasions and matched with two patients without CIDC by age, gender, and index date. The outcome, bladder cancer, was identified using ICD-O-3: C67. The incidence rate of bladder cancer was calculated as the number of bladder cancer cases divided by the total follow-up years during the study period. Cox hazards model was also used to adjust with potential confounding variables. <b>Results:</b> A total of 72,971 CIDC patients and 145,942 matched controls were analyzed. The incidence rate of bladder cancer in the CIDC group was 213.29 per 100,000 person-years, significantly higher than 40.4 per 100,000 person-years in the control group with incidence rate ratio: 5.23 (95% CI: 4.60-5.94, p<.0001). After adjusting with confoundings, patients with CIDC show a 5.16-fold higher risk of bladder cancer compared to those without (95% CI, 4.35-6.13, p<.0001). Subgroup analysis revealed a stronger association in younger patients and females. CIDC-related complications, such as urinary tract stones and benign prostatic hyperplasia (BPH), further increased bladder cancer risk. <b>Conclusion:</b> Our findings suggest a strong association between CIDC use and increased risk of bladder cancer, especially among younger patients and those with urological complications such as BPH and urinary tract stones. Additionally, comorbidities including chronic kidney disease, hypertension, and chronic obstructive pulmonary disease may contribute to this elevated risk. Therefore, an integrated healthcare strategy, including monitoring of comorbidities and complications, early cancer detection, and regular risk assessment, is critical for physicians to effectively manage bladder cancer risk in this population.