Comparison of different concepts for interpretation of chromosomal aberrations in urothelial cells detected by fluorescence in situ hybridization.

PURPOSE: Urine fluorescence in situ hybridization (FISH) has become a broadly used marker for noninvasive detection of bladder cancer (BC). However, it has been discussed whether the interpretation algorithm proposed by the manufacturer could be improved. Aim of the present study was to compare alternative evaluation strategies of FISH for detection of BC. METHODS: We included 1048 patients suspicious for BC, who underwent urine FISH examination before cystoscopy (diagnostic cohort). Herefrom, we selected 122 patients (prognostic cohort) with a history of non-muscle-invasive BC who were cystoscopically tumor free and received FISH analysis ahead of a follow-up period of 24 months. FISH results were interpreted by the algorithms of UroVysion™, Bubendorf et al. and Zellweger et al. RESULTS: In the diagnostic cohort, 228 patients (21.8%) had BC at time of evaluation; in the prognostic cohort 39 patients (32.0%) experienced tumor recurrence. Alterations in chromosome 3, 7 and 17 correlated with the presence of BC. Relative loss of 9p21 was associated with BC and higher risk for progression. The evaluation strategy proposed by Zellweger et al. showed highest accuracy of all FISH assessments. Performance of evaluation strategies differed in voided urine samples and samples obtained after mechanical manipulation. CONCLUSIONS: The performance of FISH in BC diagnosis strongly depends on the interpretation criteria. Alternative evaluation methods partly show superior diagnostic performance compared to the manufacturer's algorithm. The introduction of specific cutoffs for tetraploid cells improves specificity. Further modifications of the interpretation algorithm of the Urovysion® FISH assay have the potential to positively affect the value of this test in diagnosis and surveillance of BC.

Minimally invasive versus conventional large-bore percutaneous nephrolithotomy in the treatment of large-sized renal calculi: Surgeon's preference?

OBJECTIVE: The aim of this study was to compare the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MIP) and conventional percutaneous nephrolithotomy (PCNL) in the treatment of patients with large renal stone burden. MIP has proven its efficacy and safety in the management of small renal calculi. However, conventional PCNL is still considered the standard method for treatment of large renal stones in the upper urinary tract. MATERIALS AND METHODS: A search of two longitudinal databases in two tertiary referral centres for complex stone disease identified 133 consecutive patients who were treated by either MIP or PCNL for renal stones 20 mm or larger between January 2009 and August 2012. Clinical data and outcome measures of the two methods were compared by Student's t test, chi-squared test or Fisher's exact test. A p value less than 0.05 was considered statistically significant. RESULTS: Operative time was significantly shorter and hospital stay was significantly longer in conventional PCNL compared to MIP (p = 0.002 and < 0.001, respectively). There were no significant differences in primary stone-free rate or complication rate between the two methods. Only higher graded complications (above Clavien grade II) were significantly more common in conventional PCNL (p = 0.02). CONCLUSION: MIP is equally effective as conventional PCNL in the treatment of large renal calculi. Both methods have a similar complication rate. The shorter operative time in PCNL may be based on the larger diameter and quicker retrieval of large fragments; the longer mean hospital stay may be caused by the handling of the nephrostomy tube. The current data suggest that the choice of the method mainly depends on the surgeon's preference.