Bladder Cancer Incidence in Patients with Microhematuria at the Veterans Health Administration.

PURPOSE: Microhematuria may be a sign of underlying genitourinary pathology, but diagnoses of bladder cancer are rare among those who complete evaluations. This study determines the incidence of bladder cancer in a large cohort of patients with microhematuria, assesses the diagnostic potential of current guideline recommendations, and characterizes the relative risks of clinicodemographic factors to inform the need for microhematuria evaluation.

MATERIALS AND

METHODS

This retrospective cohort study used Veterans Health Administration and Medicare-linked data from 2015-2024 and included patients ≥18 years old diagnosed with de novo microhematuria. The main outcome was a new bladder cancer diagnosis within 2 years of index urinalysis with microhematuria. Patients were stratified by American Urologic Association risk categories to compare guideline-based risk classification with model-based estimation. The Fine-Gray method was used to estimate adjusted associations between clinicodemographic characteristics and incident bladder cancer, accounting for the competing risk of death.

RESULTS

Among 267,133 patients with microhematuria, the two-year cumulative incidences of cystoscopy completion and a new bladder cancer diagnosis were 11.9% (95% CI 11.7, 12.0) and 1.5% (95% CI 1.4, 1.5), respectively. Older age, male sex, smoking history, and ≥25 RBC/hpf were associated with a new bladder cancer diagnosis when adjusted for competing risk of death. Performance of our bladder cancer prediction model was better (ROC AUC=0.63) than that of the current AUA guidelines (AUC=0.52, p<0.001) and allowed for further risk-estimation of patients designated "high risk" by AUA criteria.

CONCLUSIONS

Estimation of patient-level microhematuria-related bladder cancer risk is possible with readily available clinicodemographic factors. Current approaches lack nuance, particularly among "high risk" patients. Precision approaches that use relative risk-factor weights and/or novel diagnostic tools may improve individualized decision-making for evaluation.