Cancer risk in bladder diverticula: a large institutional analysis of risk and management.

Purpose: Bladder diverticula (BD) are usually asymptomatic, but may increase the risk of infections, stones, or malignancy, likely due to urinary stasis within the BD. We aim to characterize the risk of bladder cancer (BC) within diverticula.

Methods: Retrospective review was conducted of patients diagnosed with BD between 1994 and 2021 at a single institution. Cancer risk was characterized using descriptive statistics and multivariable logistic regression as appropriate.

Results: We identified 764 patients with mean age 68 years, the majority of whom were male (87%) and Caucasian (86%). Of this total, 13.3% (102/764) had a diagnosis of BC and 35.3% of this subset (36/102) had definitive cancer within the BD. Diverticulectomy or partial cystectomy was performed in 13.6% (104/764), 76% of whom were preoperatively presumed to have benign disease. Surgical patients were younger and had larger BD. Of the 79 patients who underwent diverticulectomy without preoperative suspicion for cancer, 5 were incidentally diagnosed with BC on final pathology. On multivariable logistic regression, male gender [odds ratio (OR) = 2.6, p = 0.03] and increasing age (OR = 1.02, p = 0.03) were independent risk factors for BC diagnosis. Indwelling catheter, recurrent urinary tract infections (UTIs), and bladder stones did not affect the risk of BC.

Conclusions: The majority of patients with BD are not managed with surgery. BC is identified in a small but considerable proportion of patients with BD, with an even lower rate of incidentally diagnosed cancer among those undergoing BD surgery. Male gender and increasing age increased the risk of BC diagnosis.