Bladder cancer prevalence and diagnostic test accuracy: French results from the IDENTIFY study

The IDENTIFY study aimed to assess the international prevalence of bladder cancer in patients referred to urologists for evaluation of haematuria or suspicion of bladder cancer. The primary objective of this analysis was to report the French data from IDENTIFY: prevalence, diagnostic performance of urologists during cystoscopy, and diagnostic performance of the initial evaluation with ultrasound and CT scan.

A prospective study was conducted in 6 French centers from December 2017 to December 2018. All patients (>16 years) referred for cystoscopy (microscopic (NVH)/macroscopic (VH) haematuria or clinical suspicion of bladder cancer) were included. Patients with a previous diagnosis of urological cancer were excluded. Diagnostic performance was assessed by calculating sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV).

The IDENTIFY study included 261 French patients (10,896 patients included internationally). The overall prevalence of bladder cancer was 18% (95% CI 13.4-22.7). Regarding diagnostic performance, sensitivities were estimated at 70.6% (95% CI 48.9-92.3) and 58.6% (95% CI 40.7-76.6) for ultrasound and CT scan, respectively. Specificities were 95.5% (95% CI 90.6-100) and 97.7% (95% CI 95.1-100). Urologist performance in predicting stage, grade, and presence of CIS was: Se 85.7% (95% CI 59.8-100) and Sp 90.6% (95% CI 80.5-100) for stage prediction, Se 80.8% (CI 95% 65.6-95.9) et Sp 38.5% (CI 95% 12.0-64.9) for grade prediction, and Se 80% (95% CI 44.9-100) and Sp 88.6% (95% CI 78-99.1) for CIS prediction.

Nearly one in five patients referred for cystoscopy to a French urologist has bladder cancer. French urologists' cystoscopic data accurately predict stage, grade, and CIS presence in over 80% of cases. French data are consistent with international findings.