I know that my first occurrence was CIS only. There was no other tumor. When it came back, a couple years later, the CIS was invisible at first. It showed up in cytology but my uro couldn't see it.
Finally, it did show up, and it appeared to be CIS, but it had also gone deeper and had become invasive into the muscle.
I don't remember the stats, but I recall it was pretty low to have "only" CIS and more frequent to be concomitant with some other primary tumor...
Mike
Age 54
10/31/06 dx CIS (TisG3) non-invasive (at 47)
9/19/08 TURB/TUIP dx Invasive T2G3
10/8/08 RC neobladder(at 49)
2/15/13 T4G3N3M1 distant metastases(at 53)
9/2013 finished chemo -cancer free again
1/2014 ct scan results....distant mets
2/2014 ct result...spread to liver, kidneys, and lymph...