Data from Interethnic Differences in Bladder Cancer Incidence and the Association Between Type 2 Diabetes and Bladder Cancer in the Multiethnic Cohort Study

Abstract

<div>Abstract<p>Background: Research on the association between type 2 diabetes (T2D) and bladder cancer (BCA) risk among non-European ancestry populations is sparse to non-existent, and most prior studies rely on a single baseline assessment of T2D status. Methods: We estimated the T2D – BCA association using the Multiethnic Cohort Study of 185,059 men and women in California and Hawaii. Participants were African American, European American, Japanese American, Latin American, and Native Hawaiian, aged 45-75 years at enrollment (1993-1996). T2D was assessed by self-report at baseline, follow-up surveys, and Medicare claims. Cases were identified using SEER cancer registries through 2016. Associations were estimated by race/ethnicity using Cox proportional hazards regression. Adjusted attributable fractions (AAFs) and cumulative absolute risk of BCA were estimated across groups. Results: Over an average 19.7 years of follow-up 1,890 incident BCA cases were diagnosed. Time-varying T2D was associated with BCA in the multiethnic sample (HR=1.17, 95% CI, 1.05, 1.30), however the hazard ratio did not differ by race/ethnicity (p=0.85). The AAF was 4.2% in the multiethnic sample and largest among Native Hawaiians (9.8%). Absolute risk of BCA among European Americans without T2D was higher than all other groups with T2D. Conclusion: T2D is significantly associated with BCA risk in a multiethnic sample.</p></div>