Risk factors for multiple intravesical recurrences of superficial bladder cancer

To elucidate the risk factors for a second or third intravesical recurrence in patients with superficial bladder cancer.

Of 84 consecutive patients newly diagnosed as having superficial bladder cancer in Sapporo Medical University Hospital, 30 patients who had at least one recurrent superficial bladder cancer and were followed up for more than 3 years were included in this study. Multivariate analysis by Cox's proportional hazards model was used to determine which clinical and pathologic variables significantly affected the second and third recurrences. Stepwise regression analysis was used to determine which clinical and pathologic variables significantly affected multiple recurrences of bladder cancer.

The 1, 2, and 5-year recurrence-free rates as determined by the Kaplan-Meier method were 66.1%, 43.8%, and 29.8% for a second recurrence and 67.4%, 61.8%, and 39.2% for a third recurrence, respectively. Multivariate analysis revealed that only the interval between the initial transurethral resection of the bladder cancer and the first recurrence was a significant and independent factor affecting the second recurrence. In the study of the third recurrence, the interval between the first and second recurrences was the only definite risk factor for the third one. When multiple recurrences were considered, stepwise regression analysis revealed that a time of 6 months or less from the initial transurethral resection until the first recurrence was a significant factor that affected the total frequency of bladder cancer recurrence (R(2) = 0.220, P = 0.0078).

The results of our study indicate that patients will have the potential for frequent recurrences if they have the disease with recurrence after a short interval. This result may contribute to the selection of patients with superficial bladder cancer to receive aggressive adjuvant treatments to prevent frequent recurrences.