BCG for carcinoma in situ.

Bacillus Calmette-Guérin (BCG) is the most effective intravesical therapy of carcinoma in situ of the urinary bladder. Six, weekly instillations of BCG result in a complete remission in about 70-80% of patients. The optimal dose however has still to be defined, and the value of maintenance therapy is also a matter of debate. Recurrent tumours after complete remission occur mainly in the distal ureter and prostatic urethra. In these patients, cystectomy may be required. In about 60-80% of patients, local (e.g. cystitis) and/or systemic (e.g. fever, malaise) side effects are observed. The occurrence of cystitis is associated with the number of instillations, BCG dose and a positive skin test. Systemic side effects are connected with pre-existing dysuria or bacterial cystitis and with traumatic catheterization. Severe toxicity occurs in about 5% of the patients. Prognostic parameters indicating complete remission have yet to be determined, but there is evidence that cytokines detected in the urine and immune-cell infiltration into the bladder wall revealed by immunohistochemistry, can be of value in this respect.