PR patients We have 2 PR patients at 450 days. IMO there is a high chance that they are CR, as if they have been PR for so long, then positive cytology could very well be coming from Ureter and not bladder. Why do I highly suspect that this is the case, well if cancer was present in the bladder, but undetected by Cystoscope at 180 or 270 days, then most probably by day 450 CIS would be visible with cystoscope. Since it is not, then I suspect high chance that bladders are CR and UTUC is the culprit in showing a positive cytology report. All speculation on my part so don't take my word for it. I'm guessing that they will soon do an MRI to inspect ureters of pass a scope to determine final verdict on these PR patients.All IMO