Stratifying risk of urinary tract malignant tumors in patients with asymptomatic microscopic hematuria.

Abstract

223 Background: AMH in the general population is common, occurring in up to 9-18%. Even low degrees of AMH have been considered a risk factor for UTMT. Although the prevalence of UTMT is low (.01-3%), many asymptomatic patients undergo unnecessary and hazardous evaluations. In 2007, the Kaiser Permanente (KP) Urologists started a multi-year QI effort to research and develop a risk stratified evidence-based approach in the evaluation of AMH. Methods: The group first conducted a retrospective analysis to determine the incidence of urinary cancer, and stratify risk according to age, gender, smoking history, and degree of hematuria. A multi-regional prospective, observational study was then conducted over a two year period. We used a data collection tool embedded within an EMR to determine patients with AMH who are at greatest risk for UTMT, and patients who might benefit from urologic evaluation or safely avoid unnecessary workup and radiation exposure. Results: 4,414 patients had full urologic work up. Overall, 100 bladder cancers were diagnosed among 4,414 patients (2.3%), and only 11 renal cancers (0.2%) were pathologically confirmed. Multivariable logistic regression was conducted for 5 common parameters: age, gender, smoking history, degree of microscopic hematuria, and history of gross hematuria within the past 6 months. The two most important risk factors were age > 50, and prior history of gross hematuria. A hematuria risk index (HRI) was developed, which significantly improved predictability (AUC = .809-HRI vs .532-AUA guideline). Overall, 32% of the population was identified as low risk with only 0.2% cancer detected; 14% of the population was identified as high risk, of whom 11.1% had a cancer diagnosed. Conclusions: These results suggest that a considerable proportion of patients may safely avoid hazardous evaluation using multivariate risk stratification. An evidence-based algorithm was developed for the management of asymptomatic microscopic hematuria and implemented within KP. We expect to significantly improve patient safety and improve reliability of patient evaluation.