Urinary albumin excretion and cancer risk: the PREVEND cohort study

BACKGROUND: Chronic kidney disease (CKD) is believed to be associated with an increased risk for cancer, especially urinary tract cancer. However, previous studies predominantly focused on the association of decreased estimated glomerular filtration rate (eGFR) with cancer. In this study, we investigated the association of albuminuria with cancer incidence, adjusted for eGFR. METHODS: We included 8490 subjects in the Prevention of Renal and Vascular End-stage Disease (PREVEND) observational study. Urinary albumin excretion (UAE) was measured in two 24-hour urine specimens at baseline. Primary outcomes were the incidence of overall and urinary tract cancer. Secondary outcomes were the incidence of other site-specific cancers, and mortality due to overall, urinary tract, and other site-specific cancers. RESULTS: Median baseline UAE was 9.4 (IQR, 6.3–17.8) mg/24 h. During a median follow-up of 17.7 years, 1341 subjects developed cancer (of which 177 were urinary tract cancers). After multivariable adjustment including eGFR, every doubling of UAE was associated with a 6% (hazard ratios (HR), 1.06, 95% confidence intervals (CI), 1.02–1.10), and 14% (HR, 1.14, 95% CI, 1.04–1.24) higher risk of overall and urinary tract cancer incidence, respectively. Except for lung and hematological cancer, no associations were found between UAE and the incidence of other site-specific cancer. Doubling of UAE was also associated with a higher risk of mortality due to overall and lung cancer. CONCLUSIONS: Higher albuminuria is associated with a higher incidence of overall, urinary tract, lung, and hematological cancer, and with a higher risk of mortality due to overall and lung cancers, independent of baseline eGFR.