Urinary-based tumor markers enhance microhematuria risk stratification according to baseline bladder cancer prevalence

Introduction: The 2020 AUA microhematuria (MH) guideline stratifies patients into low, intermediate and high-risk for urologic malignancy based on established risk-factors for urothelial carcinoma. Notably, urine-based tumor markers (UBTMs) were not included in the risk classification. We evaluated the impact of incorporating UBTMs (cytology and multiple commercially available UBTMs) into this risk stratification. Methods: We performed a systematic review of performance characteristics of UBTMs for the detection of bladder cancer during hematuria evaluation, pooled the reported sensitivity and specificity, and calculated positive and negative likelihood ratios (LR). These were then applied to the estimated pre-test probability for the diagnosis for each AUA risk strata: low-risk 0.5%, intermediate-risk 1.0%, and high-risk (2%-3%) in order to calculate a post-test probability of bladder cancer in the event of a positive or negative test. Results: The pooled sensitivity for urinary cytology and commercially available UBTMs was 68% and 58%-95%, respectively while the specificity was estimated at 91% and 34%-90%, respectively. The positive LRs of UBTMs ranged from 2.1-7.67 and negative LRs ranged from 0.07-0.48. A negative UBTM was associated with a post-test probability of cancer for low, intermediate, and high-risk patients of 0-0.2%, 0.2%-0.5%, and 0.4%-1.1%, respectively. In the setting of a positive UBTM, the post-test probability of cancer for low, intermediate, and high-risk patients was 1.1%-3.7%, 2.1%-7.8%, 4.2%-19.2%, respectively. Conclusion: Pending prospective validation, UBTMs may be able to enhance risk stratification and inform shared decision-making over clinical factors alone and allow for re-classification of patients into higher or lower risk categories.