Superficial bladder cancer is a recurrent and potentially progressive disease. Most studies have shown that patients with a higher stage and/or grade have recurrences more frequently than do patients with a lower stage or grade. Approximately half of the lowest stage and grade tumors (Ta, Grade I/II) will recur, most of them in the first 3 months after treatment.
Carcinoma in situ recurs in up to 70% of patients. Patients with multiple tumors or very large tumors are also more likely to have recurrences (up to 80%). Only 2% of patients with Ta, Grade I (the lowest stage/grade) will progress to a more invasive tumor, whereas almost half of T1, Grade III (the highest stage/grade superficial cancer) will progress.