Risks of incident genitourinary malignancies in anticoagulated atrial fibrillation patients experiencing hematuria

Abstract Background When managing oral anticoagulant (OAC)-related bleeding in patients with atrial fibrillation (AF), the possibility of occult malignancies should be kept in mind, as suggested by guidelines. In this study, we aimed to investigate the incidence of genitourinary (GU) trat cancer in anticoagulated AF patients experiencing hematuria. Also, we aimed to report the prevalence of other causes of hematuria beside malignancy. Methods We conducted a nationwide, retrospective cohort study in Taiwan. A total of 19,974 AF patients aged ≥ 20 years on OAC treatment (warfarin 9232, non-vitamin K antagonist OACs [NOACs] 10,742) experiencing hematuria were enrolled. Risk of newly diagnosed GU malignancy within one year after hematuria was reported and compared between patients receiving warfarin and NOACs. Results A total of 738 patients (3.99%) were diagnosed to have GU tract cancers within 1 year after OAC-related hematuria, with prostate cancer (52.30%) being as the commonest subtype, followed by bladder cancer (31.71%) and kidney/ureter/urethra in origin (15.99%)(Figure 1). The risk of GU tract cancer was higher for warfarin compared to NOAC users (4.10% versus 3.89%; odds ratio 1.169, p = 0.041)(Figure 1). For patients without diagnosed GU tract cancers, urinary tract infection (42.3%) was the leading cause of hematuria followed by benign prostate hyperplasia (37.6%), GU tract stone (16.7) and cystitis (9.2%)(Figure 2). Overall, 27.5% of patients whose causes of hematuria could not be identified (Figure 2). Conclusions Incident GU cancers were diagnosed in 1 of 25 AF patients at 1 year after OAC-related hematuria. Detailed examinations for occult GU cancers and other etiologies are necessary.