Association of hematuria on microscopic urinalysis and risk of urinary tract cancer

Abstract

Purpose: We determined the incidence of urinary tract cancer in patients with hematuria, stratified risk by age, gender and hematuria degree, and examined current best policy recommendations.

Materials and methods: We performed a large, retrospective population based cohort study of patients who underwent microscopic urinalysis during 2004 and 2005 in a large managed care organization. Patients were followed for 3 years for urinary tract cancer.

Results: We identified 772,002 patients who underwent urinalysis during the study period. After exclusions due to previous hematuria, age less than 18 years, pregnancy, urinary tract infection, inpatient status and prior urinary tract cancer 309,402 patients were available for analysis, of whom 156,691 had hematuria. The overall 3-year incidence of urinary tract cancer in those with hematuria was 0.68%. Older age (greater than 40 years OR 17.0, 95% CI 11.2-25.7), greater hematuria (greater than 25 red blood cells per high power field OR 4.0, 95% CI 3.5-4.5) and male gender (OR 4.8, 95% CI 4.2-5.6) were associated with a higher risk of cancer. The American Urological Association definition of microhematuria had 50% sensitivity, 84% specificity and 1.3% positive predictive value.

Conclusions: The incidence of urinary tract cancer is low even in individuals with microhematuria. Thus, current best policy recommendations do not perform well. Since older age, male gender and greater hematuria are associated with a higher risk of cancer, future studies should evaluate strategies that target these populations.