Changes in proteinuria and the risk of urogenital cancer in Korean men

Objective: This study investigates the association between changes in proteinuria and the incidence of urogenital cancer (prostate, kidney, and bladder cancer) in Korean men. Methods: We analyzed data from 1,225,646 Korean men who underwent health check-ups in 2005–2006 and 2009. Proteinuria changes were categorized into four groups based on urine dipstick tests: persistently negative, resolved, incident, and persistent proteinuria. The relationship between these groups and the incidence of urogenital cancer over follow-up through to 2021 was assessed using multivariate Cox proportional hazards models. Results: Persistent proteinuria was associated with the highest risk of urogenital cancer (hazard ratio (HR) 1.323, 95 % confidence interval (CI) 1.190–1.472), followed by incident proteinuria (HR 1.155, 95 % CI 1.096–1.217). Kidney cancer risk was elevated in persistent (HR 2.312, 95 % CI 1.853–2.885), incident (HR 1.346, 95 % CI 1.171–1.546), and resolved (HR 1.293, 95 % CI 1.066–1.568) proteinuria groups. Bladder cancer risk increased in the incident proteinuria group (HR 1.425, 95 % CI 1.289–1.576). Resolved proteinuria was linked to a reduced risk of prostate cancer (HR 0.878, 95 % CI 0.796–0.968). Conclusion: The incidence of urogenital cancer was significantly higher for persistent proteinuria and (to a lesser degree) incident proteinuria than for persistently negative or resolved proteinuria. The risk of kidney cancer was similar to that of urogenital cancer, while other cancers had weaker associations with proteinuria. The results highlight the importance of monitoring proteinuria regularly for urogenital cancer risk assessment.