Abstract
PURPOSE: This study aimed at determining the relationship between classification according to the papillary tumor pattern of carcinoma in situ (CIS) of the bladder and prognosis, as this has not yet been well established. METHODS: This study comprised a consecutive cohort of 254 patients (primary CIS: 66 patients, stage Ta-CIS: 52 patients, and stage T1-CIS: 136 patients) with CIS-associated bladder cancer. We classified CIS according to the pathological pattern of papillary tumors and analyzed prognostic factors, including CIS classification, for progression. We evaluated progression using two endpoints: infiltrative tumors detected at stage T1 or higher or at stage T2 or higher. Bacillus Calmette-Guerin (BCG) immunotherapy response was defined as no recurrence within 6 months. RESULTS: Both the BCG immunotherapy response and CIS classification were significant prognostic factors for both the endpoints. Patients with CIS-associated stage Ta urinary bladder cancer had better prognosis for both the endpoints than those with stage T1 cancer or those with primary CIS. BCG immunotherapy response (p < 0.001) and age (p = 0.007) were also significant prognostic factors for the progression of stage T2 or higher infiltrative tumors. The prognosis of patients with recurrent primary CIS (12/26, 46.2%) and T1-CIS (25/45, 55.6%) was poor for progression; distant metastasis occurred in approximately 40% of these patients. CONCLUSIONS: Clinicians should consider radical surgery for poor prognosis in patients with recurrent CIS-associated T1 cancer or primary CIS. The CIS classification according to the tumor pattern reflects the prognosis.