Incidence, Risk Factors, and Clinical Outcomes of BCG-Related Complications

Aim: While intravesical Bacillus Calmette-Guérin (BCG) therapy provides successful outcomes in the treatment of non-muscle-invasive bladder cancer (NMIBC) due to its immunomodulatory effects, it can also lead to serious complications that may pose a life-threatening risk, albeit rarely. This study aimed to analyze the frequency, types, and clinical course of complications arising in patients who underwent intravesical BCG therapy in a tertiary healthcare center between 2019 and 2024. Additionally, findings that may contribute to the early recognition of these complications were examined. The obtained data are expected to aid in the effective management of BCG instillationrelated complications and enhance patient safety Material and Methods: A total of 400 patients who underwent intravesical BCG therapy were evaluated for complications using the hospital information management system. One hundred forty-six patients were excluded due to missing clinical/laboratory data or follow-ups conducted outside the center. The remaining 254 patients were assessed for demographic characteristics, comorbidities, smoking habits, Systemic Immune-Inflammation Index (SII), COVID-19 infection status, and complications related to BCG instillation. Results: The mean age of the patients was 66.2±9.7 years, and 225 (90%) were male. BCG-related complications were observed in 15 patients (6.0%). Primary disease relapse occurred in 87 patients (34.8%), and 30 patients (12.0%) died. The incidence of BCG-related complications was significantly higher in patients under 65 years of age compared to those aged 65 and older (12.0% vs. 2.5%; p=0.002). Patients without any comorbidities (p=0.022) and those without diabetes (p=0.005) had a statistically significant higher risk of developing BCG-related complications. Conclusion: This study highlights the challenges in managing complications associated with intravesical BCG therapy and underscores the importance of comprehensive patient monitoring to prevent adverse outcomes