MP72-03: Assessing the impact of absence of detrusor muscle in Ta-LG urothelial carcinoma of the bladder on recurrence free survival

Riccardo Mastroianni, Aldo Brassetti, Yazan Al Salhi, Umberto Anceschi, Alfredo Bove, Antonio Carbone, Cosimo De Nunzio, Andrea Fuschi, Mariaconsiglia Ferriero, Antonio Nacchia, Antonio Pastore, Giorgia Tema, Gabriele Tuderti, Giuseppe Simone

Introduction: Obtaining detrusor muscle in TURBt specimen is recommended by European Association of Urology guidelines. Few studies assessed this specific topic in the setting of Ta low-grade (LG) urothelial carcinoma (UC) of the bladder. The aim of this study was to assess if the absence of detrusor muscle at pathologic report has a negative impact on recurrence free probability in patients with a Ta LG UC of the bladder.

Methods: A multicenter TURBt database was queried for: “low-grade Ta, UC of the bladder”. All patients treated between 2008 and 2018 with tumor grade assessed according to both ISUP and WHO grading systems and with a minimum follow-up of 1-yr were included. Patients with previous history of high-grade UC were excluded. Baseline demographic, clinical and pathologic data were analyzed. EORTC risk group was recorded. Kaplan-Meier analysis was performed to assess the predictive role of clinical and pathologic data on Recurrence-Free Survival (RFS) probability, computed at 12, 36, 60 months after TURBt.

Results: Overall, 203 consecutive patients were included. Most of them were men (84%), median age was 69 yrs (IQR: 61-77). Patients and tumors characteristics were reported in Table1. At Kaplan-Meier analysis low-risk EORTC cohort displayed a significantly higher RFS probability compared with intermediate-risk cohort (5-yr probability 89.5% vs 72.4%, respectively; log-rank p=0.011. Figure 1a). At univariable Cox regression multiple tumors (HR 1.36, 95%CI 1.02-1.82; p=0.037), tumor diameter =3cm (HR 2.8, 95%CI 1.01-7.9; p=0.049), previous history of UC =1 yr (HR 1.96, 95%CI 1.02-3.75; p=0.043) and combined EORTC risk group (HR 3.15, 95%CI 1.23-8; p=0.017) were significant predictors of recurrence. Absence of detrusor muscle at pathologic report (HR 1.45, 0.61-3.45; p=0.4. Figure 1b) and adjuvant intravesical treatments (HR 0.95, 95%CI 0.5-1.78; p=0.87) had negligible impacts on RFS probabilities (Table 2).

Conclusions: EORTC risk group is a strong predictive tool to assess the risk of recurrences in patients with Ta-LG UC of the bladder. Absence of detrusor muscle in the TURBt specimen has negligible role on recurrence of patients with Ta-LG tumors, therefore it should no longer be considered as a mandatory data to assess prognosis or treatment schedule. Source of

Funding: none