Related Experiment Video
Updated: May 28, 2026
Magnetic Resonance Imaging Assessment of Carcinogen-induced Murine Bladder Tumors
Published on: March 29, 2019
A new and highly prognostic system to discern T1 bladder cancer substage
Bas W G van Rhijn1, Theo H van der Kwast, Sultan S Alkhateeb
1Department of Surgical Oncology, Division of Urology, University Health Network, Princess Margaret Hospital, Toronto, Canada. b.v.rhijn@nki.nl
Background:
Management of T1 bladder cancer (BCa) is controversial.
Objective:
Evaluate the impact of substage on the clinical outcome of T1 BCa.
Design, Setting, And Participants:
The T1 diagnosis of 134 first-diagnosis BCa patients from two university hospitals was confirmed. For the T1 substage, we used a new system that discerns T1-microinvasive (T1m) and T1-extensive-invasive (T1e) tumors. We then determined the invasion of the muscularis mucosae-vascular plexus (MM-VP): T1a (invasion above the MM-VP), T1b (invasion in the MM-VP), or T1c (invasion beyond the MM-VP). If the MM-VP was not present at the invasion front, the case was assigned to T1a or T1c. All patients were initially managed conservatively (with bacillus Calmette-Guérin).
Measurements:
Multivariable analyses for progression and disease-specific survival (DSS).
Results And Limitations:
Median follow-up was 6.4 yr (interquartile range: 3.3-9.2 yr). Progression to ≥ T2 was observed in 40 patients (30%), and 19 patients (14%) died of BCa. The MM-VP was not present at the invasion front in 50 patients (37%). T1 substage was as follows: 40 T1m and 94 T1e; 81 T1a, 18 T1b, and 35 T1c. In multivariable analyses, substage (T1m/T1e) was significant for progression (p=0.001) and DSS (p=0.032), whereas substage according to T1a/T1b/T1c was not significant. Female gender (p=0.006) and carcinoma in situ (p=0.034) were also significant predictors of progression. The main limitation to the study is absence of a repeat transurethral resection.
Conclusions:
Substage according to the new system (T1m and T1e) was user-friendly, possible in 100% of cases, and very predictive of T1 BCa behavior. Future studies may ultimately lead to the incorporation of this new substaging system in the TNM classification system for urinary BCa.
