Investigating Bladder Chemotherapy Instead of Surgery for Low Risk Bladder Cancer

Inclusion Criteria: * Written informed consent * NMIBC recurrence following original diagnosis of low risk NMIBC (defined as Ta G1 or Ta G2 (Ta low grade) with a risk of recurrence score of ≤6 using EORTC risk tables * Histologically confirmed Transitional-cell carcinoma (TCC) at original diagnosis * Aged 16 or over * Satisfactory pre-treatment haematology values and serum creatinine \< 1.5 x Upper Limit of Normal (ULN) * Negative pregnancy test for women of child-bearing potential Exclusion Criteria: * Any history of: grade 3/high grade or ≥T1 transitional cell carcinoma, concomitant carcinoma in situ, more than 7 tumours at one diagnosis or more than 1 recurrence per year since initial diagnosis or in the past five years, whichever is shorter * Any history of histologically confirmed non-TCC bladder cancer * Trial entry recurrence identified within 11.5 months of the date of the original diagnosis * Any prior treatment of the trial entry recurrence (including biopsy) * Previous MMC chemotherapy other than a single instillation at diagnostic surgery * Known allergy to MMC * Carcinoma involving the prostatic urethra or upper urinary tract (participants should have had imaging of the upper urinary tract within 2 years prior to randomisation) * Known or suspected reduced bladder capacity (\<100ml) * Significant bleeding disorder * Female patients who are breast-feeding or are of childbearing potential and unwilling or unable to use adequate non-hormonal contraception. Male p…