Microhaematuria: 1.5% had a new bladder cancer within two years, and current risk groups discriminated poorly

Design

Retrospective cohort with Fine-Gray competing-risk models, 2015 to 2024

Population

267,133 US veterans with de novo microhaematuria

Primary outcome

New bladder cancer diagnosis within 2 years of the index urinalysis

Effect

2-year incidence 1.5% (95% CI 1.4 to 1.5); model AUC 0.63 vs AUA categories 0.52

This retrospective study used linked US veterans' and Medicare data from 2015 to 2024 for 267,133 patients with newly diagnosed microhaematuria.

Within two years, 11.9% had cystoscopy and 1.5% (95% CI 1.4 to 1.5) had a new bladder cancer diagnosis. After allowing for death as a competing risk, older age, male sex, smoking history and 25 or more red cells per high-power field were associated with cancer. The authors' prediction model (AUC 0.63) discriminated better than the current American Urological Association risk categories (AUC 0.52), though both are weak, and the model discriminated within the guideline's high-risk group.

Bladder cancer was uncommon, and the study could only count cancers that were diagnosed, which depends on who was investigated. It argues for more individualised evaluation, not for dropping evaluation.

• Keep evaluating microhaematuria in high-risk patients, including older men and smokers.
• Document smoking history and the red cell count when deciding who gets cystoscopy.
• Do not rely on risk categories alone; their discrimination was close to chance here.
• Consider shared decision-making for low-risk patients, as cancer was uncommon.
• Follow current local guidance, which this study does not replace.

Why it matters

Most patients sent for evaluation do not have cancer, and better selection could spare some of them an invasive test.

Don't overread it

A US veteran population, mostly men, and only diagnosed cancers were counted; it does not support reducing evaluation of high-risk patients.

The statistics, in plain English

An AUC of 0.52 is little better than a coin toss; 0.63 is still modest. Only about one in eight patients had cystoscopy, so cancers may have been missed in those not examined, which makes the true incidence uncertain.

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