Intravesical mitomycin C for carcinoma in situ of the urinary bladder.

Mitomycin C was given intravesically over periods of 2-32 months to 34 patients with carcinoma in situ of the urinary bladder. Initial complete response was obtained in 17 patients, 14 of whom remained without evidence of disease during follow-up averaging 28 months from cessation of mitomycin therapy. In three responding patients malignant cells reappeared in the urine during follow-up, although no recurrence of carcinoma could be proven in bladder biopsy specimens. In eight of the 17 non-responders, muscle invasion and/or metastatic disease developed during or after mitomycin treatment. The prostatic urethra was involved in five cases. Chemotherapy had to be discontinued because of chemical cystitis in three cases. Mitomycin C appears to be effective for intravesical treatment of carcinoma in situ of the urinary bladder. Close surveillance of these patients is mandatory, however, and must include monitoring not only of the bladder, but also of the prostatic urethra and the upper urinary tract.