Androgen Suppression Therapy Is Associated with Lower Recurrence of Non-muscle-invasive Bladder Cancer

Abstract

Background: The challenge of managing non-muscle-invasive bladder cancer (NMIBC) is its high recurrence rate. Clinical investigations have begun to explore the role of androgen suppression as an adjunct to bladder cancer (BC) treatment.

Objective: To examine the effect of androgen suppression therapy (AST) on recurrence and progression rate of risk-stratified NMIBC.

Design, setting, and participants: Male patients with NMIBC were identified retrospectively from a US institutional database between 2001 and 2017. AST included 5α-reductase inhibitor, gonadotropin-releasing hormone agonist, and antiandrogen. Patients who were exposed to AST prior to documented recurrence/progression were included in the treatment arm. BC was risk stratified to investigate the differential response to AST.

Outcome measurements and statistical analysis: Hazard ratios (HRs) for NMIBC recurrence and progression were estimated using Cox proportional hazards multivariate regression models with stepwise method. Recurrence-free survival (RFS) and progression-free survival (PFS) were compared between groups with and without AST.

Results and limitations: We identified a total of 274 males with a median follow-up period of 3.1 yr (interquartile range [IQR] 1.5-5.2). Thirty-six patients were exposed to AST with a median duration of 1.7 yr (IQR 0.7-2.6). AST was associated with a lower risk of recurrence (HR 0.53, 95% confidence interval 0.30-0.88) as well as improved RFS (p = 0.014). However, no significant reduction of progression or improvement of PFS (p = 0.23) was found with AST. After risk stratification, all five patients who progressed in the AST cohort had high-risk disease on initial transurethral resection (TUR), whereas no patients with low/intermediate-risk disease progressed on AST. Limitations of the study include nonstandardized initiation of AST in relation to initial TUR, lack of androgen level quantification, and small sample size in the treatment arm.

Conclusions: In this retrospective, single-institution study, AST was associated with a lower risk of recurrence in NMIBC. No significant association between AST and progression was found. Further investigation is warranted to define the role of AST as an adjunctive therapy for NMIBC.

Patient summary: Non-muscle-invasive bladder cancer is a highly recurrent disease that often requires patients to undergo repeated surgical treatments. This single-institution report suggests that medical suppression of androgen may be a potential preventive therapy to reduce recurrence in certain patients.

Keywords: Androgen antagonist; Bladder cancer; Non–muscle invasive; Prevention and control; Progression; Recurrence; Risk stratification.