AUA 2020: Evaluation of the Patient with MicroHematuria in 2020: The New Guidelines and Beyond

(UroToday.com) Jay D. Raman, MD, FACS, provided an overview of the 2020 updated AUA microhematuria (MH) guidelines which will be released in the near future. He highlighted areas in the management of MH that have changed since 2012 and presented the rationale for these changes. He began his lecture by noting that hematuria is one of the most common urologic diagnoses, accounting for 27% of all urologic evaluations. Among healthy participants, screening studies note a 6.5% prevalence of hematuria, with ranges from 2.4-31.1%.  Differential diagnosis is important, as MH can be a sign of renal malignancy, stones, infections, trauma; to name a few.  Dr. Raman noted the risk of malignancy was shown in a prospective observational study (DETECT 1; ClinicalTrials.gov: NCT02676180) of 3556 patients referred to 40 UK hospitals for evaluation of hematuria who received cystoscopy and upper tract imaging.  There was a 10% incidence of urinary tract cancer (8% bladder, 1% renal, 0.7% upper tract, 0.3% prostate). 

An astonishing figure that Dr. Ramen noted was <50% of patients with hematuria are referred for urologic evaluation and for women, only 28% are referred. A nationwide claims-based investigation by Cohn and colleagues (2014) noted that the days from onset of hematuria, to eventual diagnosis was longer in women as a differential diagnosis in women is often attributed to a gynecologic source or to a UTI.  Women are also less likely to receive testing (e.g. imaging).  In addition to sex disparities in the evaluation of hematuria, there are shortcomings and gaps in the evaluation of at-risk populations (e.g. African-American men and women). 

Dr. Ramen provided a detailed review of current guidelines on MH, noting the inconsistencies.  Linder and colleagues reviewed the hematuria guidelines from the American Urological Association; the consensus statement by the Canadian Urological Association, Canadian Urologic Oncology Group and Bladder Cancer Canada; the American College of Physicians; the Joint Consensus Statement of the Renal Association and British Association of Urological Surgeons; and the National Institute for Health and Care Excellence, noting variability in definition, identification of who should receive an evaluation and the type and its timeframe.  And a problem with the 2012 AUA MH guideline was that is recommended testing, CT program and cystoscopy, in all patient so as to minimize missing a malignancy while not taking into account those patients who are at-risk.  Also, testing is costly and the CT urogram increases the patient’s life-time exposure to ionizing radiation, theoretically increasing the risk of radiation-induced cancer as noted by Georgieva and colleagues.

The 2020 AUA guideline on MH is a paradigm shift, as it is recommending a more individualized evaluation that should be tailored to the risk, which accepting that this approach may not identify every urinary tract cancer.  But the guideline goals are to standardize the evaluation, so it minimizes variation and decreases the risk of a delayed diagnosis, with a final objective to avoid unnecessary evaluation in low-risk patients.  The following are some of the guideline specifics:

  • Definition: > 3 RBC/HPF on microscopic evaluation of a single, properly collected specimen
  • Should not be defined by dipstick alone but a positive dipstick should prompt formal microscopic evaluation.  Many factors can contribute to a false positive dipstick (e.g. dehydration, exercise, menstrual blood, etc). 
  • Perform same evaluation on patients with MH whether or not on anticoagulation or anti-platelet therapy (Strong Recommendation; Evidence Level C) 
  • If hematuria is related to a UTI, perform a urine culture documenting a UTI and repeat a U/A after UTI resolves.  The concern is women with UTIs have irritative voiding symptoms (urgency, frequency), also presenting symptoms of bladder cancer. The guideline does not specify the time to repeat the testing.
  • Does not recommend urine cytology or urine-based biomarkers in the initial evaluation but can be used if MH persists and risk factors are present. (Strong Recommendation; Evidence Level C)

The 2020 MH guideline has added a risk stratification, categorizing the MH as low, intermediate, or high-risk depending on gender, age, smoking HX (former smokers or tobacco chewers have the same risk as a current smoker), the persistence of MH and HX of gross hematuria.  Dr. Ramen reviewed the different risk categories outlined in this updated guideline. The guideline also introduces “shared-decision making” as to repeating UA in 6 months or moving forward with cystoscopy and renal ultrasound.  An example of movement on the risk scale would be an initial low-risk patient with persistent hematuria on repeat testing would be reclassified as intermediate or high-risk and move on to evaluation with cystoscopy and upper tract imaging. 

For a low-risk patient, the overall risk for malignancy is low and imaging itself is a risk. A strong recommendation for a patient categorized as an immediate risk would be cystoscopy and renal ultrasound. Although a CT Urogram is more sensitive than a renal ultrasound in detecting upper tract malignancy, the guideline recommends a renal ultrasound for an intermediate-risk patient, as the overall rate of upper tract urologic cancer is low. Halpern and colleagues (2017) noted that the cost-effectiveness of common diagnostic approaches for asymptomatic MH should be considered. 

A high-risk evaluation for malignancy would include cystoscopy and axial upper tract imaging.  Dr Ramen noted the preferred upper tract study would be a multiphasic CT urogram.  He discussed the differences between the standard and split-dose CT urograms.  Split dose protocol can reduce radiation risk.  Relative and absolute contraindications for CT Urogram include 1st-trimester pregnancy and impaired renal function.  If the patient has allergies to iodinated dye, pre-medicate with steroids or antihistamines.  If the patient has a contraindication to multiphasic CT, then a magnetic resonance urogram is indicated. 

Final key points: if a patient has gross hematuria, considered a high risk.  Hematuria can be waxing and waning in nature so if the patient is initially considered low risk, then has return of persistent MH, move to immediate risk evaluation. 

Presented by: Jay D. Raman, MD, FACS, Professor and Chief of Urology, Penn State Health, Milton S. Hershey Medical Center, Hershey, PA

Written by: Diane Newman, DNP, ANP-BC, Adjunct Professor of Urology in Surgery, Perelman School of Medicine, University of Pennsylvania and Co-Director of the Penn Center for Continence and Pelvic Health

References:

  1. Ark et al. Variation in the Diagnostic Evaluation among Persons with Hematuria: Influence of Gender, Race and Risk Factors for Bladder Cancer. Urol. 2017 Nov;198(5):1033-1038. doi: 10.1016/j.juro.2017.06.083.
  2. Cohn et al. Sex disparities in diagnosis of bladder cancer after initial presentation with hematuria: a nationwide claims-based investigation. Cancer. 2014 Feb 15;120(4):555-61. doi: 10.1002/cncr.28416
  3. Davis  et al. Diagnosis, evaluation and follow-up of asymptomatic microhematuria (AMH) in adults: AUA guideline. J Urol. 2012 Dec;188(6 Suppl):2473-81. doi: 10.1016/j.juro.2012.09.078
  4. Georgieva et al, Comparison of the Harms, Advantages, and Costs Associated With Alternative Guidelines for the Evaluation of Hematuria. JAMA Intern Med. 2019 Jul 29;179(10):1352-62. doi: 10.1001/jamainternmed.2019.2280.
  5. Halpern et al. Cost-effectiveness of Common Diagnostic Approaches for Evaluation of Asymptomatic Microscopic Hematuria. JAMA Intern Med. 2017 Jun 1;177(6):800-807. doi: 10.1001/jamainternmed.2017.0739
email news signup