Clinical significance of random bladder biopsy in primary T1 bladder cancer

The clinical significance of random bladder biopsies in primary non-muscle-invasive bladder cancer is unclear. The present study investigated the significance of positive random bladder biopsies in primary T1 NMIBC. The present study retrospectively reviewed the records of 71 patients with primary pT1N0M0 bladder cancer who underwent transurethral resection of the bladder tumor (TURBT) and concomitant random bladder biopsy. A total of 12 patients who received cystectomy immediately following the TURBT were excluded, and the remaining 59 patients were included in the analysis. Random bladder biopsy was defined as a cold-cup biopsy of pre-specified normal-looking areas in the bladder. The association of clinicopathological factors, including random biopsy results, with intravesical recurrence were assessed by univariate and multivariate Cox proportional hazards analyses. Of the 59 patients, 15 (25%) demonstrated carcinoma in situ (CIS) lesions on random bladder biopsy: Five (33%) in biopsy specimens alone and the remaining 10 (67%) in biopsy and TUR specimens. Positive random biopsy was associated with preoperative positive urine cytology (P=0.011) and small size of the main tumor (P=0.008). Multivariate analysis demonstrated positive random biopsy as the sole independent poor prognostic factor for intravesical recurrence (hazard ratio: 4.69, P=0.014). The five patients who had CIS detected in biopsy specimens alone had worse, although non-significantly worse, recurrence-free survival compared with those with CIS detected in biopsy and TUR specimens (P=0.100). In conclusion, positive bladder random biopsy, equivalent to the presence of CIS, was an independent predictor of recurrence in primary T1 bladder cancer. Given that one-third of CIS lesions could not have been detected without biopsy, random bladder biopsy should be considered for patients with T1 tumors.