Area deprivation and cancer‐specific mortality in non‐muscle‐invasive bladder cancer: a statewide analysis

Objectives: To evaluate whether neighbourhood socioeconomic deprivation, measured by the Area Deprivation Index (ADI), is associated with cancer-specific mortality (CSM) in patients with non-muscle-invasive bladder cancer (NMIBC). Patients and methods: We retrospectively reviewed patients with NMIBC (T stage <2, node-negative, non-metastatic) from Michigan Cancer Surveillance Program (2004-2019). ADI national percentiles were assigned based on residential census block groups and stratified into quartiles, with the fourth quartile (ADI 75-100) being the most deprived. Cumulative incidence functions compared CSM between quartiles, and competing-risk regression analysis assessed the association between ADI and CSM after adjusting for covariates. Results: Among 19 722 patients (92.2% non-Hispanic White; median [interquartile range] age 72 [64-80] years; 76.7% male), most resided in metropolitan areas (81%) and 61% were married. Overall, 8.5%, 26.4%, 34.9%, and 30.2% of patients were in the first, second, third, and fourth ADI quartile, respectively. At 10 years, the cumulative incidence of CSM was 7.3%, 7.9%, 8.7%, and 9.7% across the first-fourth quartiles, respectively (P = 0.002). At the competing risk analysis, each 25-point increase in ADI was associated with a 6% higher hazard of CSM (95% confidence interval 1.01-1.12; P = 0.032). Older age, higher T stage, unmarried status, and Medicaid insurance were independently associated with greater CSM. Conclusions: Higher ADI was associated with increased CSM in our cohort. Evaluating socioeconomic context in NMIBC care may inform follow-up and therapy and, potentially, influence progression and mortality.