Association of coexisting amyloidosis with survival outcomes in bladder cancer: A real-world cohort study.

Abstract

650 Background: Bladder cancer (BC) is one of the most prevalent urologic malignancies. Amyloidosis, characterized by extracellular deposition of amyloid fibrils, may coexist with cancer but remains underexplored as a comorbidity affecting cancer outcomes. This study compares clinical outcomes, including mortality and urinary incontinence, between patients with BC alone and those with concurrent BC and amyloidosis. Methods: We conducted a retrospective cohort study using the TriNetX Global Collaborative Network, comprising data from 157 healthcare organizations worldwide. Two cohorts were defined: (1) patients with a diagnosis of malignant neoplasm of the bladder (ICD-10-CM: C67) and (2) patients with both bladder cancer and amyloidosis (ICD-10-CM: E85). Propensity score matching (PSM) was performed 1:1 to balance demographics and comorbidities. Outcomes were assessed over a 12-month follow-up window using risk analysis and Kaplan-Meier survival methods. Results: Before matching, 412,823 patients had BC alone, and 1,488 had BC with amyloidosis. After PSM, each cohort included 1,375 patients. Mean age was 76.9 years in both groups, and 80.5% were male. Mortality: The 1-year mortality risk was 12.4% for BC alone vs 17.2% for BC+amyloidosis (Risk Difference: −0.048; p < 0.001). Kaplan-Meier analysis showed reduced survival in the BC+amyloidosis group (log-rank p = 0.000; HR = 0.701, 95% CI 0.576–0.854). Urinary Incontinence: Incidence was similar between groups (1.5% vs 1.7%, p = 0.652), with no significant differences in mean instance frequency or time-to-event analysis ( p = 0.623). Conclusions: Coexistent amyloidosis in patients with bladder cancer is associated with significantly higher short-term mortality, independent of age, sex, and comorbidities like hypertension, and diabetes. However, urinary incontinence outcomes did not differ significantly suggesting that amyloidosis does not directly exacerbate lower urinary tract dysfunction in the short term.. Amyloidosis may represent a marker of systemic frailty influencing survival in bladder cancer populations. To our knowledge, this is the first large-scale comparative study evaluating the clinical characteristics and outcomes of bladder cancer patients with coexisting amyloidosis. Our findings reveal that this rare comorbidity is associated with inferior survival outcomes, underscoring the need for multidisciplinary management and tailored therapeutic strategies. Keywords: Bladder cancer, Amyloidosis, TriNetX, Propensity score matching, Mortality, Survival analysis.