RE:RE:RE:RE:RE:RE:RE:RE:Bored. Waiting. Here is some playing with data to look at. Thanks for the great educational post Dawg. So that's how they do a urine cytology.
In terms of a "cure" an important part of the treatment is that the cancer cell death induced by Ruvidar PDT is immunogenic, which is to say it generates a long lasting anti-tumour immune response along with an anti-cancer vaccination effect, such that if the same type of cancer recurs anywhere in the body the immune system will recognize and destroy those cancer cells.
This is a well known effect of photodynamic therapy quite apart from Theralase. Theralase demonstrated this effect way back in the small animal days when it could not get cancer cells to "take" when they injected them into mice after they had been treated with TLD1433.PDT for that kind of cancer.
So even if some urothelial cancer cells manage to escape the first onslaught of Ruvidar PDT, the patient's immune system is apt to take over and be on the lookout for any recurrence of cells of that type of cancer so it can take appropriate action!
This could well be why the first 13 patients were still cancer free 12 months after their first cancer-free evaluation at 90 days. For the 13 I think it is appropriate to say they have been cured of that kind of cancer.
DJDawg wrote: Good quote Eog.
I work in an area that sees patients with a different kind of cancer (thyroid). The nature of cancer is to proliferate and spread (locally or distant). The patients in these trials had cancers that were fast enough to proliferate that BCG didn't keep it down or remove it. If they were treated with an agent that was 98% effective but still ieft some 2% cells viable then those cells will become the basis or the cancer relapse. Usually when someone says that the cancer is back after x amount of time it is not really back but rather at a size that make itself known again. For many cancers, there is a window after which you can say that if it were present it would have declared.
I am not saying I know as much with bladder cancer but if 6 or 9 months have passed and nothing on cytology that would be a long way to saying that patient is likely cured. Cytology is where you spin down the urine sample so that it is just a clump of cells. Then you spread out the clump and stain it with agents that will show cancer cells standing out. In bladder cancer, it wouldn't tough a lot of cancer to have cells start sloughing off and being present in urine (before seen on scope).
So while I don't think you can say "cured" lightly, I would say that if a patient has no sign of a rapidly proliferating cell line, 9 months after last treatment (450 days) then it is "likely" that they are cured.