Evaluating BCG Therapy in High- and Low-Grade Non-Muscle-Invasive Bladder Cancer: Insights from a Latvian Hospital (2019–2024)

Bacillus Calmette-Guérin (BCG) immunotherapy is a cornerstone treatment for managing non-muscle invasive bladder cancer (NMIBC), which is one of the most common cancers in Europe. However, real-world adherence and outcomes vary significantly. The aim of the study was to evaluate recurrence free survival (RFS), progression free survival (PFS), overall survival (OS), and treatment implementation among the NMIBC patients treated with BCG, compared to those treated with transurethral resection of bladder tumour (TURB) alone at Latvia’s second largest university hospital. A retrospective cohort study was conducted at Pauls Stradiņš Clinical University Hospital. Patients diagnosed with NMIBC between 2019 and 2024 were divided into two groups: BCG-treated and TURB-only. Kaplan-Meier analysis was used to evaluate survival outcomes, and Cox regression assessed predictors of recurrence. Among 111 BCG and 167 TURB-only patients, three-year RFS was significantly higher in the BCG group for T1HG patients (75% vs. 45%, p < 0.05). BCG was associated with a 59% lower recurrence risk (HR: 0.41, 95% CI: 0.23–0.77; p < 0.05). No significant differences were observed in PFS or OS. Only 4% of BCG patients completed optimal maintenance therapy. BCG significantly improves RFS in T1HG NMIBC, but is limited by poor maintenance adherence, thus highlighting the need for better implementation and larger prospective studies.