First, welcome to a club you didn't want to join! I can really appreciate your topic title...."with questions." You have just discovered one of the "dirty little secrets" of bladder cancer...it tends to come back.
BCG is currently the most effective treatment, especially for high grade. I HOPE
that now that you have finished the six initial treatments, your urologist has scheduled you for a series of maintenance treatments. These have been shown to increase the effectiveness of BCG significantly. There are other drugs that are used, such as Mitomycin C, but they are not as effective and are usually used when, for some reason, BCG cannot.
Don't agonize over the statistics. You can find statistics all over the map on effectiveness. I have seen some that are better than the 60% you quote, and maintenance treatments improve on those significantly.
Finally, BE SURE TO KEEP YOUR CYSTOSCOPY APPOINTMENTS. If there should be recurrences, you want them found early. It is much premature to be overly worried about bladder removal (easy for her to say!) because the odds are that it won't happen. But if it does, and if the recurrences are caught early, it IS the real cure. There are many who regularly post on this Forum who live very full lives without a bladder...car racing, scuba diving. It would not be the end of the world.
Be sure to ask us any questions you have.
And best of luck to you!!
Sara Anne