Introduction: Intravesical bacillus Calmette-Guérin (BCG) therapy is the gold standard adjuvant treatment for patients with high-grade non-muscle-invasive bladder cancer (NMIBC). Despite the association between metabolic syndrome (MetS) and bladder cancer, the association between MetS and BCG failure is unknown. The objective of this study was to characterize disease recurrence following BCG in patients with and without MetS.
Methods: We retrospectively evaluated the records of patients undergoing TURBT at our institution in 2012-2015 for NMIBC and identified those who received adjuvant BCG therapy. MetS was defined as having three of four components: diabetes mellitus, hyperlipidemia, hypertension, or body mass index (BMI)≥30kg/m2. The primary outcome was recurrence or progression. Descriptive statistics, chi-squared analysis, Kaplan-Meier survival analysis, and Cox multivariable regression analyses were performed.
Results: High grade was present in 83/90 (92.2%) patients. MetS was present in 27/90 (30%) patients. Median follow-up was 20 months. On Kaplan-Meier analysis, patients with MetS had worse DFS compared with patient without MetS. On multivariable analysis, BMI≥30 kg/m2 was a significant predictor of recurrence or progression (HR 2.94, 95% CI: 1.43-6.03). Presence of MetS did not significantly affect the type of BCG failure.
Conclusions: The association between MetS and failure to respond to BCG therapy is multifactorial but is in part associated with obesity. Elevated BMI is strongly associated with recurrence or progression. Further studies are warranted to investigate the relationship between increased adiposity and response to BCG, especially as other novel immunotherapeutic agents are likely to enter the NMIBC space.
Keywords: Bladder Cancer; Calmette-Guérin Bacillus; Metabolic Syndrome; Outcome Assessment; Recurrence.