A randomized controlled trial of short-term vs. long-term prophylactic intravesical instillation chemotherapy for recurrence after transurethral resection of Ta/T1 transitional cell carcinoma of the bladder: Koga H, Kuroiwa K, Yamaguchi A, Osada Y, Tsuneyoshi M, Naito S, Department of Urology, Graduate School of Medicine, Kyushu University, Japan