Assessing the Impact of the Absence of Detrusor Muscle in Ta Low-grade Urothelial Carcinoma of the Bladder on Recurrence-free Survival.

Obtaining detrusor muscle (DM) in transurethral resection of bladder tumor (TURBt) specimen is considered a surrogate marker of resection quality. However, evidence was principally investigated in high-risk tumors. Therefore, DM sampling for low-grade (LG) urothelial carcinoma (UC) remains poorly investigated and certainly requires further investigation.

To assess whether the absence of DM in TURBt specimen has a negative impact on recurrence-free survival (RFS) in patients with a Ta LG UC.

A multicenter TURBt database was queried for "LG, Ta, UC of the bladder." All patients treated between 1996 and 2018 with tumor grade assessed according to both 1973 World Health Organization and 2004 WHO/International Society of Urological Pathology grading classifications and with a minimum follow-up of 1 yr were included. Patients with a previous history of high-grade UC, upper urinary tract UC, or bladder tumor differentiations other than UC were excluded.

TURBt.

Baseline demographic, clinical, and pathologic data were analyzed. The European Organization for Research and Treatment of Cancer (EORTC) risk group was recorded. Kaplan-Meier analysis was performed to assess the predictive role of clinical and pathologic data for RFS. Univariable and multivariable Cox regression analyses were performed to identify the predictors of recurrence.

Overall, 521 patients were included. At Kaplan-Meier analysis, the low-risk cohort displayed significantly higher RFS than the intermediate-risk cohort (1-yr RFS 87% vs 79%; log-rank p = 0.007). At univariable Cox regression analysis, only gender, multiple tumors, tumor diameter ≥3 cm, and EORTC risk group were significant predictors of recurrence. Absence of DM had no impact on RFS. Multivariable Cox regression analysis confirmed gender and EORTC risk group as independent predictors of recurrence.

Absence of DM in TURBt specimen has negligible role in RFS of patients with Ta LG tumors of the bladder.

In this study, we assessed the role that detrusor muscle (DM) in transurethral resection of bladder tumor specimen has in recurrence-free survival, in patients with a Ta low-grade urothelial carcinoma of the bladder. Absence of DM has no impact on tumor recurrence; therefore, it does not require additional attention.

European urology focus. 2020 Sep 05 [Epub ahead of print]

Riccardo Mastroianni, Ado Brassetti, Wojciech Krajewsky, Romuald Zdrojowy, Yazan Al Salhi, Umberto Anceschi, Alfredo Maria Bove, Antonio Carbone, Cosimo De Nunzio, Andrea Fuschi, Mariaconsiglia Ferriero, Antonio Nacchia, Antonio Luigi Pastore, Giorgia Tema, Gabriele Tuderti, Michele Gallucci, Giuseppe Simone

Department of Urology, "Regina Elena" National Cancer Institute, Rome, Italy; Department of Urology, "Sapienza" University, Rome, Italy. Electronic address: ., Department of Urology, "Regina Elena" National Cancer Institute, Rome, Italy., Department of Urology and Urological Oncology, Wrocław Medical University, Wrocław, Poland., Department of Medico Surgical Sciences and Biotechnologies-Urology Unit, "Sapienza" University-I.C.O.T., Latina, Italy., Department of Urology, "Sant'Andrea" Hospital, Rome, Italy., Department of Urology, "Sapienza" University, Rome, Italy.