Assessing treatment response after intravesical bacillus Calmette-Guerin induction cycle: are routine bladder biopsies necessary?

purposeTo determine the need for routine bladder biopsies (BBs) in assessing response to the induction cycle of intravesical bacillus Calmette-Guérin (BCG) for high-risk non-muscle-invasive bladder cancer (NMIBC).

methodsOur prospectively maintained NMIBC database was queried to identify patients with high-risk disease (carcinoma in situ, high-grade Ta/T1) who underwent BBs after BCG induction cycle. Urine cytology, cystoscopy, and BBs findings were evaluated.

resultsA total of 219 patients met the inclusion criteria. Urine cytology was positive in 20 patients and negative in 199; cystoscopy was positive in 35 patients, suspicious in 32 and normal in 152 patients. BBs yielded bladder cancer (BCa) in 43 (19.6%) patients, with a BCa rate of 9.3% in patients with negative cytology and cystoscopy as opposed to 38.0% in patients whereby one or both exams were suspicious/positive. The diagnostic accuracy of urine cytology, cystoscopy, and combined tests was 0.56, 0.70, and 0.71, respectively. The negative predictive value of combined tests was 90.7%. Performing BBs only in patients with positive cytology and/or positive/suspicious cystoscopy would have spared 140 (64%) patients to undergo this procedure while missing BCa in 13 (9.3%) of them, representing 30% of all BCa cases.

conclusionPerforming BBs only in patients with positive cytology and suspicious/positive cystoscopy would spare 64% of un-necessary BBs but miss a non-negligible number of BCas. While no data are available regarding the potential consequences of missing such BCas, such information should be taken into account in patient's counselling.