Physician group issues advice, raises questions about best practices for evaluating blood in the urine as a sign of cancer

"Blood in the urine can have many causes, and may be associated with urinary tract cancers including bladder cancer and cancer of the upper urinary tract," said Matt Nielsen, MD, MS, a UNC Lineberger member, co-director of the Multidisciplinary Urologic Oncology Program and associate professor of urology in the UNC School of Medicine. "But, given how common this finding is in clinical practice, we need to ensure that follow-up testing is done in a way that properly balances all of the potential harms and benefits of testing."

There is little controversy surrounding evaluation of patients with gross hematuria, which is blood in the urine visible to the naked eye, the paper reports. The ACP advises that all adults with gross hematuria should be referred for further urologic evaluation, even if the symptoms have stopped, given the relatively high risk this symptom has for underlying cancer.

More commonly, patients may have a small amount of blood in the urine that is discovered only through testing. The cancer risk is lower for microscopic hematuria than that associated with gross hematuria, and there is a lack of clarity regarding indications for specific diagnostic testing strategies for individual patients, Nielsen said.

For suspicion of hematuria raised based on the findings of what is known as a "dipstick" test, the ACP advises that physicians confirm that finding using a microscope before further evaluation.

Physicians should consider referring adults with microscopically confirmed hematuria for evaluation by a urologist using cystoscopy and imaging in the absence of another possible, demonstrable and benign cause for it, the report suggests. However, they also pointed to the potential harms associated with cystoscopy -- anxiety, discomfort and possible infection from endoscopic evaluation of the bladder -- as well as potential harms linked to CT imaging.

They point to the increasing recognition of potential longer-term harms of imaging given the evidence linking radiation doses associated with CT scans to increased cancer risk. Acknowledging that the association between radiation exposure from CT imaging and lifetime cancer risk has only been indirectly estimated, they call for further scrutiny of the issue.

"There is a great interest in reducing the costs of care, but the orientation of this paper toward value seeks to look at costs in the patient-centered context of the risk/benefit balance," Nielsen said. "The paper highlights some important unanswered questions in this context with respect to radiation exposure from CT scans, and in particular for people who have a very low risk of cancer associated with hematuria."

Nielsen said that researchers at UNC, with partners from around the country, are planning to study innovative approaches for testing that's tailored based on patients' risk profiles.

"Some health systems have implemented alternative approaches in real-world practice that might point to a better balance of benefit and risk," he said.