Diagnostic random bladder biopsies: reflections from a population-based cohort of 538 patients

To assess whether diagnostic random bladder biopsies and the detection of concomitant carcinoma in situ (CIS) have an impact on the frequency of intravesical bacille Calmette-Guérin (BCG) instillations or radical cystectomy; and whether this affects the cancer-specific survival in patients with pTaG3 or pT1G1-G3 transitional cell carcinoma of the urinary bladder.

A population-based cohort of 538 patients with newly diagnosed bladder cancer was prospectively registered in the Stockholm County during 1995 and 1996 and followed for more than 5 years.

Random biopsies were recommended in all patients but the decision to take biopsies was made by the treating urologist and hence performed in 326 out of 538 patients (61%), which revealed concomitant CIS in 47 patients(14%). Sixty out of 103 (58%) patients with pTaG3 or pT1G1-G3 tumours, in whom random biopsies were performed, received intravesical BCG compared with five out of 22 patients (23%) where random biopsies were not taken (p = 0.004). Moreover, 23 out of 103 patients (22%) with pTaG3 or pT1G1-G3 tumours in whom random biopsies were performed underwent radical cystectomy compared with none out of 22 patients (0%) without random biopsies (p = 0.013). The Cox proportional hazard ratio for death due to bladder cancer in patients with pTaG3 or pT1G1-G3 tumours among patients not having versus having undergone random biopsies was 2.5 (95% confidence interval 1.1-5.6).

Patients diagnosed in Stockholm in 1995 or 1996 with pTaG3 or pT1G1-G3 bladder tumours having undergone random bladder biopsies more frequently underwent BCG treatment and radical cystectomy and had higher cancer-specific survival than patients who did not undergo random biopsies.