Combined morphologic and fluorescence in situ hybridization analysis of voided urine samples for the detection and follow-up of bladder cancer in patients with benign urine cytology
Bladder cancer is among the five most common malignancies worldwide. Patients with bladder cancer are closely followed with periodic cystoscopies and urine cytology analyses due to the significant risk of tumor recurrence. The UroVysion fluorescence in situ hybridization (FISH) test demonstrated higher sensitivity over urine cytology in detecting bladder cancer by most comparative studies.Methods
In the current study, the diagnostic usefulness of a combined cytology and FISH analysis approach was tested using the Duet automatic scanning system in patients with benign urine cytology who were being monitored for recurrent urothelial carcinoma or being assessed for various urologic symptoms.Results
By combining the benefits of conventional cytology with molecular diagnostics, a more sensitive detection of bladder cancer was attained. All patients who had positive cystoscopy concomitantly with urine sampling were detected by combined analysis. Additional patients who developed transitional cell carcinoma during a follow-up period of 24 months had a previous positive result on combined analysis. Only 2 patients with a negative combined analysis result presented with late disease recurrence (20 months and 22 months, respectively, after the negative test). Therefore, negative combined analysis was found to be predictive of a lack of disease recurrence for at least 12 months. In this timeframe, the overall sensitivity, specificity, negative predictive value (NPV), and positive predictive values of the combined analysis test were 100%, 65%, 100%, and 44%, respectively.Conclusions
Given the absolute sensitivity and NPV of the combined analysis test, the management of patients with a negative combined analysis result might be revised and allow for more flexible assessment and management of bladder cancer patients relying more on urine bound tests.
Daniely and colleagues performed fluorescence in situ hybridization (FISH) on urinary sediment using an automated reader. Their data confirms data from manual assessment of FISH on urine specimens (J Urol 2002;168:1950–54). This molecular assay can detect bladder cancers earlier than they can be seen by cystoscopy. However, it must be remembered that a positive FISH test is not the same as biopsy proven cancer and in this study had only a positive predictive value of 44%. Patients with a positive FISH should be evaluated carefully and followed closely but directing therapy based solely on a positive FISH is risky. This study also showed that FISH had excellent negative predictive value. As suggested by the authors, it is reasonable to use this information to prolong the cystoscopic intervals in patients, particularly those with low risk disease.