You're not "back to square one", you've just done 99.9% of the job of killing the cancer, pretty much any other anti-cancer method will finish the job for you.
It's possible that at some point before a tumor developed there were 99.9% of cells that should have killed themselves actually doing so. The
That's not to say it isn't worth pursuing. It could be very effective, but just remember all the other ways nature has already tried to do what you're doing before you get too excited