Bladder cancer test increases accuracy of cystoscopy

A point-of-care bladder cancer test (NMP22 BladderChek, Matritech, Newton, MA) increases the accuracy of cystoscopy, according to results of a large, multicenter study published in this week's JAMA (2005; 293:810-6).

When used with cystoscopy, the test detected 94% of bladder cancers, compared with 89% detected by cystoscopy alone. The NMP22 test also identified four invasive, life-threatening cancers missed during cystoscopy, and it detected more than three times as many malignancies as cytology.

"We found that when cystoscopy and the NMP22 test are used together, they detect bladder cancer at a 94% rate," said lead author H. Barton Grossman, MD, of M.D. Anderson Cancer Center, Houston. "In our study, the test identified several malignancies, including life-threatening tumors, missed by the initial cystoscopy."

Researchers from 23 academic, private practice, and veterans' facilities prospectively enrolled 1,331 patients who had elevated risk of bladder cancer due to history of smoking or clinical symptoms. Patients provided a voided urine sample for the NMP22 test and cytology prior to undergoing cystoscopy.

Seventy-nine patients were diagnosed with bladder cancer. Of those, 44 patients had a positive NMP22 assay, for a sensitivity of 55.7%. Twelve of 76 patients had a positive cytology test, for a sensitivity of 15.8%. The specificity of the NMP22 assay was 85.7%, compared with 99.2%% for cytology.