Microscopic Traces of Blood in Urine Linked to Urological Cancer

By Marilynn Larkin

December 18, 2019

NEW YORK (Reuters Health) - Non-visible hematuria (NVH) was associated with bladder cancer (BC), upper tract urothelial carcinoma (UTUC) and kidney cancer (KC) in a systematic review and meta-analysis.

"NVH is common, but the incidence of underlying urological cancer is less so," Dr. Marcus Cumberbatch of the University of Sheffield, UK, said in an email to Reuters Health. "The downstream tests to investigate a positive result are very expensive. Therefore, there is a large cost: benefit ratio which researchers in the field are seeking to refine and reduce in order to make the heavily burdened diagnostic pathway more efficient, and potentially less invasive to patients."

"To date," he noted, "we are yet to see a better biomarker than blood in the urine for these diseases."

"Historically, screening studies for BC in particular have shown a survival benefit and also a stage migration (more superficial cancer and less invasive) in screened populations compared to non-screened," he said. "But, the cost of nationwide screening has been prohibitively high. It has also been unclear how to roll out the testing - i.e., how many dipstick tests per patient, which age group, how often to test and in combination with which imaging technology?"

"The aim of this study was to see if we could arrive at an evidenced-based recommendation for urologists across the world and to fuel a screening project for BC and KC," he said.

The study, published in European Urology, included 78 papers overall; 40 - reporting on close to 20,000 patients - were included in the meta-analysis.

Overall, fewer than 1% of patients were found to have a urological cancer after a negative NVH evaluation. The likelihood of a urological cancer in patients with NVH increased with age (40 years or older), male sex, and cigarette smoking.

Cancer detection rates in individuals evaluated for NVH ranged from 0% to 16% for BC in 37 studies; 0% to 3.5% for UTUC in 30 studies; and 0% to 9.7% for KC in 29 studies. However, there was substantial statistical heterogeneity when calculating the rates, and most patients were not adequately evaluated, according to the authors.

Further, there was large variability in NVH criteria both in the literature and guidelines, making comparisons difficult.

Nonetheless, the authors recommend that patients 40 and over with dipstick-positive hematuria and no clear precipitating cause should be evaluated; the evaluation should include cystoscopy and ultrasound or computed tomography urogram imaging of the upper tract (no need for urine cytology); and, if findings are unremarkable, re-evaluation of high-risk patients and those with new symptoms.

Dr. Roby Thomas, a hematologist oncologist at UPMC Hillman Cancer Center in Pennsylvania, commented by email, "Most patients with NVH are not evaluated (and) followed up appropriately. We need to do a better job educating clinicians, especially at the primary care level, of what should be the next steps - and if clinical suspicion is high, a urology referral is warranted."

"Consensus guidelines are always hard to put into practice, and need to be considered on a case by case basis," he told Reuters Health. "Age, gender, and ethnicity are considerations."

"Prospective data would be best to use," he noted. "It also it would be interesting to see NHV urology referral rates as compared to visible hematuria."

"CT urograms also carry an increased risk of radiation exposure (negligible, but much more than ultrasound), and IV contrast exposure as well, which is not mentioned directly in the article," he added.

SOURCE: http://bit.ly/2S2skUZ European Urology, online November 29, 2019.