Scared

My husband was diagnosed with Transitional Cell carcinoma in March. It had gone to his kindney so it had to be removed. The dr. told us that the thought he had gotten it all . He then had more tests and it had spread to his lungs . He went throuhg more chemo and it appeared to have stopped it . Then 9 more weeks of chemo and then more tests . Some in his lung had gotten smaller but others had grown. It had also gone to his liver but tests showed the lver is funtioning. The dr. said that the ccancer had become resistent to the medecine so he changed it. Now 8 more weeks and more tests . Has anyone gone through this where they change the medecine either once or more times and have some positive results ? I was devestated that it was not working . I am very scared .