Low diagnostic yield with cystoscopy and CT urography for urinary tract cancers

Reuters Health - 11/05/2021 - Few patients with microhematuria who undergo evaluation for urinary tract cancers with cystoscopy or computed tomographic urography are diagnosed with a malignancy, a systematic review and meta-analysis suggests.

Researchers examined data from 30 studies with a total of 24,366 patients evaluated for microhematuria. Overall, a total of 488 urinary tract cancers were diagnosed, and the pooled detection rate among all patients was 1.85%.

The pooled diagnostic yield overall was 2.00% for bladder cancer, 0.18% for kidney cell carcinoma, and 0.02% for upper tract urothelial carcinoma.

"The primary fear that microscopic hematuria is associated with urogenital cancer seems to be unjustified," said lead study author Dr. Sharon Waisbrod of the department of urology at Spital-Limmattal in Schlieren, Switzerland, and the University Hospital of Zurich.

"We suspected that the diagnostic yield would be low, but were surprised on how low the yield really is especially for upper tract urothelial cancer," Dr. Waisbrod said by email.

The study results are particularly unexpected because evaluation with computed tomography or cystoscopy for microscopic hematuria is common practice and was until very recently recommended by the American Urological Association, Dr. Waisbrod added.

"It seems not only unnecessary and expensive but also exposing patients in danger of further needless invasive procedures as a result of false positive findings," Dr. Waisbrod said.

In subgroup analysis of studies that had at least 95% of the cohort undergo cystoscopy, the bladder cancer detection rate was 2.74%. And in the seven studies with high-risk cohorts, the bladder cancer detection rate was 4.61%.

For upper tract urothelial carcinoma, subgroup analysis of studies that had at least 95% of the cohort undergo CT urography found a pooled detection rate of 0.09%. The pooled detection rate was 0.45% in studies of high-risk cohorts.

Subgroup analysis of studies that had at least 95% of the cohort undergo CT urography for kidney cell carcinoma found a pooled detection rate of 0.10%.

One limitation of the analysis is the heterogeneity of the included studies regarding factors such as the inclusion criteria, definitions of microhematuria, assessment of hematuria, and exclusion of urinary tract infections, researchers note in JAMA Network Open.

However, the study results are consistent with findings from the AUA, which suggest genitourinary malignancies are detected in 3% of patients with microhematuria, said Dr. Wassim Kassouf, head of urologic oncology at McGill University Health Center in Montreal.

The results underscore that higher-risk patients such as males, adults over 50 years, and current or former smokers may be the individuals who benefit most from cystoscopy and CT urography in evaluations for microhematuria, Dr. Kassouf, who wasn't involved in the study, said by email.

"The majority of patients, even if high-risk, will still have normal findings on investigation for microhematuria," Dr. Kassouf said. "As such, we need to better refine our current risk-stratification for microhematuria to avoid unnecessary and invasive investigations for our patients."

SOURCE: https://bit.ly/3fczLmt JAMA Network Open, online May 10, 2021.

By Lisa Rapaport



Posted on 11 May 202124 May 2021