Value of separate tumor base biopsy in transurethral resection of bladder tumors

Introduction The aim of our study was to evaluate whether a biopsy from the tumor base after transurethral resection of bladder tumor (TURBT) has an impact on subsequent management of patients with bladder tumors. While tumor base biopsy at the completion of TURBT is a common practice, there is no definition of its role within the major international professional guidelines. Material and methods We retrospectively reviewed the records of consecutive patients undergoing TURBT between 2015 and 2019 at our institution. We recorded demographic and tumor characteristics of initial TURBT, tumor base biopsy and restaging TURBT pathology outcomes. The pathologic outcomes were correlated to assess the additional value of a separate tumor base biopsy. Results A total of 532 patients underwent TURBT. A separate tumor base biopsy after completion of TURBT was performed in 154 patients. The mean patient's age was 72.8 ±11.7 years (range 48-94) and 119 (77.2%) were men. In 40 patients (25.9%) muscle was absent in the pathological specimen of the tumor resection. Muscle was present in all but 6 (3.9%) tumor base biopsies. Of the 33 patients who underwent repeated transurethral resection for pT1 tumors, 2 had residual low-grade pTa, 1 had residual high-grade pT1, and 3 patients were upstaged to pT2. Conclusions Although tumor base biopsy at the completion of TURBT is a common practice, our analysis fails to demonstrate any tangible benefit in the staging of bladder tumors. In our experience tumor base biopsy did not change the management in patients with superficial or muscle invasive disease.