Hello @judith4, Welcome to Mayo Clinic Connect. There is a post by @predictable in another discussion that you might find helpful - https://connect.mayoclinic.org/discussion/vitamin-c-for-cancer-treatment/. @predictable may be able to share his experience with you.

While we wait for other members to respond, you may find the following Mayo Clinic page helpful - Bladder cancer care at Mayo Clinic: https://www.mayoclinic.org/diseases-conditions/bladder-cancer/care-at-mayo-clinic/mac-20356112

Did the doctor think that surgery to remove the small tumor is the next step?