How is prognosis and tx of T1 high grade urothelial cancer CIS?

Intravesical infusion of BCG (vaccine of tuberculosis): Immunotherapy to destruct all cancer cells: BCG induce immunological reactions in bladder (Macrophages and mastocytes phagocyte cancer cells and recurrence/progression rate is much lower). Chemotherapy does not work on CIS even though it’s superficial (Exam question) N.B: It is a misconception that superficial tumors we always give chemotherapy