[Staging of infiltrating bladder cancer. Role of C.T. scan].

Objectives: To analyse the role of CT-scan on preoperative determination of bladder and lymph node involvement of infiltrative bladder cancer, and its possible impact on the surgical management of these patients.

Methods: Retrospective study including 115 patients with the diagnosis of infiltrative bladder cancer between 1984 and 1999. The ability of CT-scan for bladder and lymph node staging was evaluated comparing results with the findings after radical surgery. Potential impact of this imaging technique on change of surgical attitudes was evaluated.

Results: Perivesical involvement estimation by CT-scan was right in 36.5%, underestimated in 49.6% and overestimated in 14%. The more advanced the perivesical involvement the lower the sensitivity for CT-scan in perivesical staging. The more locally advanced tumour the higher specificity, oscillating between 44% for pT2 and 94% for pT4. In reference to lymph node staging, it was correct in 71.3% of the cases, although this percentage depended almost exclusively on patients with negative nodes (N-). However, there was a 24.3% understaging rate which corresponded to the majority of N+ patients. These data offer a 28% sensitivity, 93% specificity, 68% positive predictive value, and 72% negative predictive value. Finally, the reliability of bladder staging in patients with lymph node involvement (N+) (39 patients) was established; it was correctly estimated in as low as 30% of the cases with a 70% understaging rate. CT-scan would have modified surgical attitudes in only 6 patients (5%), all of them with advanced tumours.

Conclusions: The impact of CT-scan on infiltrative bladder cancer clinical staging is relatively low. The highest benefit is obtained in patients suspect of having advanced disease. Limitation to this group would result in significative cost reductions with low risk for unappropriate surgical management.