Second Transurethral Resection (TUR) for Bladder Cancer Diagnosed with High Grade pT1 by Initial TUR Under Narrow Band Imaging

Abstract

We evaluated 52 consecutive cases of patients undergoing second transurethral resections (TUR) for non-muscle invasive bladder cancer (NMIBC) in which the patients were diagnosed with high grade pT1 by the initial TUR under narrow band imaging (NBI). The initial TUR under NBI (NBI-TUR) was performed : Systematic intravesical observation under white light imaging (WLI) and NBI was followed by a multiple site biopsy (MSB), after which lesions detected in positive findings were resected completely under NBI. The tumor detection rates under WLI and NBI were calculated separately and compared with endoscopic findings and MSB samples. The second TUR was performed as a resection that included the surrounding mucosa and muscle layer of the initial NBI-TUR scar under WLI observation, 4-8 weeks after the initial NBI-TUR. The patients were divided into two groups : The residual cancer lesion-positive group (NBIR positive), and the residual cancer lesion-negative group (NBIR negative). The tumor detection rate under NBI was more sensitive compared with that under WLI in the initial NBI-TUR (89.4% vs 59.1% p< 0.0001), and the residual cancer detection rate in the 2nd TUR reached 34.6% (18/52). There was no significant difference in the background factors between the NBIR positive and NBIR negative. While the number of cancer lesions detected under NBI was significantly higher than that under WLI in the NMIBCdiagnosed high grade pT1, the rate of cancer lesions that were difficult to identify in the initial NBI-TUR was still high. These findings demonstrate the limitations of the mono-therapeutic effect of NBI-TUR.