The quality of bladder resection improves the histological characterization of bladder cancer. an analysis based on rare variant histotypes

October 2020

European Urology Open Science 20:S159

DOI:10.1016/S2666-1683(20)35594-4

Authors

Stefano Tappero, Stefano Parodi, Guglielmo Mantica, F. Dotta, D. Ndrevataj, Andrea Pacchetti, N. Testino, Alberto Caviglia, Martina Beverini, R. Malinaric, F. Ambrosini, G. Guano, Francesco Chierigo, S. Rebuffo, P. Traverso, Marco Borghesi, N. Suardi, Carlo Terrone.

Abstract

Introduction: Histology is one of the most important factors determining the prognosis of bladder cancer (BCa) patients and the presence of rare variant foci (RVF) may impact disease-specific survival as compared to pure transitional cell carcinoma (TCC). RVF identification at the time of trans-urethral resection of the bladder (TURB) is of utmost importance for the planning of the best multimodal approach. However, the concordance rate of RVF between TURB and radical cystectomy (RC) is suboptimal. We hypothesized that surgical factors may have an impact on identification of RVF at TURB.

Materials and methods: Between 2000 and 2019 all consecutive patients treated at a single tertiary referral center with RC and pathological evidence of RVF were identified. The histological type of the RC specimen was compared to the histological findings at TURB. Both procedures were performed at the same institution and the specimens analyzed by a dedicated uro-pathologist. The analyses focused on the identification of surgical factors predicting the concordance between TURB and RC histotypes. Surgical factors considered were maximal core length (MCL) at TURB pathology and type of resector used (mono- vs. bipolar). Covariates consisted of age, sex, tumor size and focality (mono- vs. multifocal). For variables comparison between patients with and without RVF concordance Student’s t-test and Chi-squared test were used for continuous and categorical variables, respectively. Moreover, uni- and multivariable logistic regression analyses were used to test the role of surgical factors in predicting concordance between TURB and RC.

Results: A total of 81 consecutive patients with RVF at RC were included. 49 patients (60.5%) had RVFat TURB whereas 32 (39.5%) had pure TCC at TURB. No differences between the two groups were found in terms of age ( p = 0.42), sex ( p = 0.34), tumor size ( p = 0.13) nor focality ( p = 0.06). When the analyses targeted the surgical factors, patients with concordance had longer MCL (12.5 vs. 10 mm, p = 0.01) while no differences were noted between mono- and bi-polar resection ( p = 0.34). At univariable logistic regression analyses, MCL was significantly correlated to higher rate of concordance between TURB and RC [OR 1.15 (1.02–1.29); p = 0.02]. At multivariable analyses, adjusting for age, sex, tumor focality and size, MCL represented an indepentent predictor of higher concordance [OR 1.13 (1.00–1.29); p = 0.04]. MCL was then stratified in two categories (>= 10 mm vs. <10 mm) and maintained independent prognostic significance at multivariable analyses [OR 3.4 (1.19–9.83); p = 0.02].

Conclusions: When the length of the specimens at TURB is over 10 mm the concordance rate of RVF between TURB and RC is higher. Therefore, the qualityof resection is of paramount importance in order to provide the pathologist with the highest quality of the tissue. Our data yield support towards en-bloc resection when feasible. Taken together, our data might have important implications for planning the best multimodal treatment before RC.