Comprehensive Evaluation of Bacillus Calmette–Guérin therapy in Non-muscle invasive bladder cancer Egyptian patients: a retrospective cohort study

Abstract Background Bladder cancer ranks among the most prevalent genitourinary malignancies globally, demanding comprehensive management strategies. Bacille Calmette-Guerin (BCG) therapy, a standard for Non-Muscle Invasive Bladder Cancer (NMIBC), is integral to treatment, yet debates persist regarding its optimal application. Aim This research aims to elucidate potential correlations and implications for BCG immunotherapy. Moreover, explores the impact of BCG-induced localized and systemic side effects on NMIBC outcome, addressing the need for a nuanced understanding of its therapeutic and adverse effects. Patients and methods Patients’ data was sourced from NMIBC patient files at The National Cancer Institute—Cairo University, comprising a total of 150 patients’ files. Demographic and pathological data, BCG side effects, performance status (PS), recurrences and progression were recorded. The European Organization for Research and Treatment of Cancer (EORTC) score guided risk assessment was employed. ALP, urea and creatinine levels were also assessed at baseline and after the 1st, 3rd, and 6th dose of BCG to establish correlations with the number of BCG doses administered. Results An association emerges, indicating that the dosage of BCG therapy significantly influences recurrence-free survival. Remarkably, patients receiving more than 10 doses showed significantly lower recurrence-free survival (RFS) compared to those administered fewer than 10 doses ( p  = 0.001). Univariate analysis showed that patients who received ≥ 10 BCG doses had worse RFS compared to those who received < 10 BCG doses (Hazard Ratio (HR): 4 [95% confidence interval (CI): 2.4–6.7]), p  < 0.001. The study reveals a remarkable correlation between the elevation of ALP, urea, and creatinine levels and the number of BCG doses administered. On multivariate analysis, the only independent factor that significantly affects the RFS was number of doses of BCG. Patients who received ≥ 10 doses had worse RFS compared to those who received < 10 doses (HR: 3.8 [95%CI: 1.8–8.1]), p  = 0.001. Cardiac comorbidity negatively impacted the PFS with P -value (0.016). The only significant pathological parameter impacting OS was grade of tumor, P -value (0.025). Moreover, size of tumor influenced RFS, P -value (0.001). Clear relation between diabetes mellitus and tumor size was observed; where larger tumor size was more prevalent in diabetic patients and reflected as shorter RFS . Significant localized adverse effects included increased frequency of urination, pus in urine, and urgency. Pus in urine doubled the risk of recurrence-free survival (RFS). 6.1% reported vomiting and 23.5% experienced fever. Performance status tended to decline post BCG doses. Patients who had vomiting episodes had worse outcome ( p  = 0.01). Conclusion The current findings suggest that cardiac comorbidity, high tumor grade and large size might be evaluated as independent poor prognostic factors for Egyptian NMIBC patients. Performance status decline correlated with BCG therapy; tuberculosis-like symptoms were undetected in the currently studied cohort due to the mass vaccination program implemented in Egypt. The research also highlights the impact of the number of BCG doses and ALP baseline on patients’ outcome, providing valuable insights into the sophisticated relationship between treatment intensity and key biomarkers in NMIBC management.