Objective: The aim of this study was to compare, in order to increase our ability to detect bladder cancer, the predictive power of narrow band imaging (NBI) versus white light cystoscopy (WL). The secondary objective was to evaluate how the preoperative use of NBI cystoscopy can increase the ability to detect bladder lesions in terms of status, multi-focality and dimensions. Materials and methods: Between June 2010 and April 2012, 797 consecutive patients, 423 male and 374 female, affected by suspected bladder cancer lesions, underwent to WL plus NBI cystoscopy and subsequently to WL Bipolar Gyrus PK (Olympus, Tokyo, Japan) transurethral resection of bladder tumour (WL-TURBT). The average follow-up was 24 (16-38) months. Mean age was 67.7 yrs. (range 46-88). All the patients underwent by same surgeon to WL resection (WL-TURBT) of the previously identified lesions by same surgeon. All the removed tissue was sent separately for histological evaluation after mapping the areas of resection on a topographic sheet. Results: In our study we considered 797 patients that matched our inclusion criteria. Through the use of WL cystoscopy, we identified 603 patients (75.53%) with suspicious lesions, instead, with the use of light NBI, we found 786 patients with suspicious lesions (98.49%).The use of NBI cystoscopy increases by approximately 30% the specific ability to detect lesions not otherwise visible with WL cystoscopy (OR 21.9 and RR 1.30), in particular for patients with lesions size < 3 cm (OR 24.00; RR 1.40), unifocal (OR: 22.28; RR 1.47) and recurrent (OR 58.4; RR 1.34). Pathology demonstrated the presence of cancer in 512 (64.2%) patients, of whom 412 (51.8%) were visible both with WL cystoscopy and NBI cystoscopy. In our experience, only 11 (1.38%) lesions were only positive at WL cystoscopy (negative at NBI cystoscopy) thus 501 (62.8%, OR 10.13; RR 1.21) patients showed bladder oncological lesions positive at NBI cystoscopy. In these patients, the use the NBI Cystoscopy has better highlighted a recurrence (p < 0.005; OR 22.8, RR 1.23; 95% CI-1.13 to 0.24) or a lesion < 3 cm (p < 0.05; OR 11.4 , RR 1.30; 95% CI-0.18 to 0.29) or a unifocal lesion (p < 0.005; OR 10.38, RR 1.34, CI 0.18 to 0.30). Conclusions: The use of NBI cystoscopy, significantly increases by approximately 30% our predictive power to identify neoplastic lesions, especially unifocal or < 3 cm or recurrent lesions. Following WLTURBT, stage, dimension and focaliity are statistically significant determinants (p < 0.001) of the bladder oncological lesions detected by NBI cystoscopy rather than by WL cystoscopy.
Bladder cancer; Narrow band imaging (NBI); Cystoscopy; Bipolar TURBT