I would strongly second Alan's recommendation that you DEMAND a second opinion. .. "HIGH GRADE" by definition means that the cells are rapidly dividing and have the potential to spread FAST. The recommendation that you have been given is the standard for LOW GRADE.
The good news is that there are several really good places to get a second opinion in Southern California. Keck School of Medicine, USC, is one of the world renown centers for treatment of bladder cancer. The bad news is that it is difficult, from what I have heard, to get Kaiser to allow you to talk to anyone outside their closed system.
Best of luck..and do get a second opinion from a really good urologist who specializes in bladder cancer treatment.
Sara Anne