A simple, routine urine test could offer an early clue to cancer risk—long before symptoms appear.

A new analysis in the British Journal of Cancer reports that people with albuminuria—protein leaking into the urine—had a higher risk of developing cancer, even when kidney filtration looked normal. The finding comes from an individual‑participant meta‑analysis of 54 cohorts in the global CKD Prognosis Consortium, covering 1.3 million adults with lab‑measured urine albumin and more than 3.5 million with dipstick protein tests. Participants were cancer‑free at the start of follow‑up; overall cancer occurred at a rate of about 17 per 1,000 person‑years.    

What the researchers found

• Dose–response link with albuminuria. Compared with very low urine albumin (<10 mg/g), cancer risk rose steadily across higher categories: 10–29 mg/g (≈10% higher risk), 30–299 mg/g (≈16% higher), and ≥300 mg/g (≈26% higher). By contrast, reduced kidney filtration (eGFR) wasn’t linked to overall cancer risk.  
• Even “trace” protein mattered. A positive result as mild as trace on a standard urine dipstick was associated with a modest increase in risk.  
• Across many cancer types. Higher urine albumin tracked with increased risk for several cancers—including lung, kidney, head and neck, colorectal, liver, pancreas, larynx, leukemia, and multiple myeloma. For example, per eight‑fold rise in urine albumin, the hazard ratio was ~1.20 for lung cancer, ~1.22 for kidney cancer, ~1.29 for urological cancers overall, and ~1.42 for multiple myeloma. Lower eGFR related mainly to urological cancers and multiple myeloma.    
• Consistent across subgroups. Results were similar after accounting for age, sex, smoking, diabetes, blood pressure, cholesterol and even when analyses started one year after baseline to reduce reverse causality.  

Why this matters

Albuminuria is already checked in primary care to monitor diabetes and high blood pressure. The new data suggest it may double as a general risk marker for future cancer, not only for kidney or urinary tract malignancies but also for lung and several others. The authors propose that chronic inflammation, blood‑vessel dysfunction, and shared exposures like air pollution could help explain the link—ideas that need testing in mechanistic studies.  

Important caveats

This was an observational analysis that can’t prove cause and effect. People with albuminuria differed from others in ways that might still influence cancer risk; measurements and cancer ascertainment also varied by cohort, and genetic predisposition wasn’t assessed. The authors caution that albuminuria should not yet be used to qualify people for extra cancer screening until benefits, harms, and cost‑effectiveness are evaluated.  

What this means for you

• If a past test showed protein in your urine, talk with your clinician. It’s a signal to manage cardiovascular and kidney risks aggressively—and to stay on track with age‑appropriate cancer screening you already qualify for.  
• If you live with diabetes or high blood pressure, ask whether you’re due for an albuminuria test; it’s a quick check that may reveal broader health risks.  

The bottom line: In one of the largest studies of its kind, albumin in the urine emerged as a robust, dose‑dependent marker of higher cancer risk, whereas standard measures of kidney filtration were largely not. More research will determine whether—and how—this simple test should inform future cancer prevention strategies.    

Source: Mok, Y., Surapaneni, A., Sang, Y., Coresh, J., Grams, M. E., Matsushita, K., Ballew, S. H., Alencar de Pinho, N., Ärnlöv, J., Barreto, S. M., Bell, S., Brenner, H., Carrero, J. J., Chinnadurai, R., Ciemins, E., Gansevoort, R. T., Jassal, S. K., Jung, K. J., Kirchner, H. L., Konta, T., … CKD Prognosis Consortium (2025). Chronic kidney disease and incident cancer risk: an individual participant data meta-analysis. British journal of cancer, 10.1038/s41416-025-03140-z. Advance online publication. https://doi.org/10.1038/s41416-025-03140-z

Editor’s note: This article is for information only and is not a substitute for professional medical advice.