T1 diagnosis of 134 first-diagnosis Bladder Cancer was confirmed.
For T1 sub-stage, we used a new system that discerns T1-micro-invasive (T1m) and T1-extensive-invasive (T1e) tumors.
Secondly, we determined the invasion of the muscularis mucosae (MM) – vascular plexus (VP), i.e. T1a (invasion above MM-VP) / T1b / T1c (invasion beyond 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 (BCG).
Multivariable analyses for progression and disease specific survival were performed.