Risk of incident genitourinary cancer following hematuria in patients with atrial fibrillation receiving oral anticoagulants

BACKGROUND: Hematuria is common in patients with atrial fibrillation (AF) on oral anticoagulants (OACs). However, risks of incident genitourinary (GU) malignancy and detailed etiologies of hematuria have not been well studied.

OBJECTIVE: We aimed to investigate the risk of hematuria and underlying GU malignancy in patients with AF receiving OACs.

METHODS: A total of 192,728 patients with AF receiving OACs were identified from Taiwan National Health Insurance Research Database. The risk of hematuria was compared between patients receiving warfarin (n = 75,541) and non-vitamin K antagonist OACs (NOACs) (n = 117,187). Among them, 18,509 patients experiencing hematuria without previous history of GU malignancy were defined as the study population. One-year risks of GU cancers were studied and compared between warfarin and NOAC users.

RESULTS: Compared with warfarin, NOACs were associated with a higher risk of mild (2.29% per year vs 1.71% per year, adjusted hazard ratio [aHR] 1.107, P < .0001) or moderate hematuria (0.84% per year vs 0.62% per year, aHR 1.075, P = .0189), but a lower risk of severe hematuria (0.15% per year vs 0.17% per year, aHR 0.630, P < .0001). Within 1 year after hematuria, 738 (3.99%) patients were diagnosed with incident GU cancers, and the risk was higher among warfarin compared with NOAC users (4.10% vs 3.89%, odds ratio [OR] 1.1169, P = .041). Age ≥75 years (OR 1.486, P < .0001), male gender (OR 2.342, P < .0001) and abnormal renal function (OR 1.319, P = .0015) were important clinical factors associated with the diagnosis of GU cancer.

CONCLUSION: GU malignancy occurs in approximately 4% of anticoagulated patients with AF experiencing hematuria. Comprehensive evaluations of underlying etiologies of hematuria are necessary.