Necrosis simply refers to the appearance of some tumors that are dying. If the central part of a tumor dies, the tumor tissue becomes liquid, and that gives the appearance we call "necrosis". As for the issue of chemotherapy, bladder cancer usually responds pretty well to chemotherapy, but doesn't get cured, and when it comes back, we don't have much that helps. There are other drugs that can be tried, depending on what he is getting now, but with each course of treatment the benefit becomes less and the side effects greater. I normally offer my patients two courses of therapy (Your husband is getting his first course(the six treatments) and I've seen some pretty good second line responses. But unfortunately we don't have anything that cures this cancer once it has spread to other tissues. Hope this helps.