Letters Section Editor: Robert M. Golub, MD, Senior Editor.
To the Editor: In their study of methods to detect recurrent bladder cancer, Dr Grossman and colleagues1 compared an NMP22 assay with voided urine cytology as supplements to the reference standard, cystoscopy. The addition of voided urine cytology did not significantly increase sensitivity compared with cystoscopy alone (94% vs 91%), whereas the addition of the NMP22 assay did improve sensitivity (99% vs 91%). However, the sensitivity of voided urine cytology was markedly lower than in previous reports. In a recent review of urine markers for bladder cancer surveillance,2 voided urine cytology sensitivity by tumor grade was available from 7 individual studies. The sensitivity by tumor grade reported by Grossman et al was inferior to the corresponding grade from each of these 7 studies. Unusually poor voided urine cytology sensitivity as a comparison raises concerns regarding the apparent advantage of using NMP22, and it is therefore important to know why the voided urine cytology sensitivity was so low in this study.
Eggener S, Herr H. NMP22 and Surveillance for Recurrent Bladder Cancer. JAMA. 2006;296(1):44-46. doi:10.1001/jama.296.1.45-a