5. No UC in the urethra, excluded by visual inspection during cystoscopy and, in addition, in patients with (i) tumour of trigone (ii) tumour of bladder neck (iii) abnormal prostatic urethra UC must be excluded by biopsy of the prostatic urethra in all male patients or, in female patients, from the portion of the urethra adjacent to the bladder neck, before study recruitment.