What is the available evidence to support immediate adjuvant intravesical chemotherapy after transurethral resection of superficial transitional cell carcinoma of the bladder?

The endpoints chosen for analysis of outcome following intravesical therapy can be quite varied. Precise definitions of endpoints are mandatory to permit any comparative assessment between agents or treatment regimens. Although the recurrence endpoint favorably impacts on quality of life by reducing the number of biopsies and resections, the endpoint of greatest importance is progression. Progression of disease is an indication for cystectomy. Unfortunately, the majority of trials testing intravesical agents have not shown significant reduction in disease progression or have been too small or followed for too short an interval to be able to adequately measure this endpoint. Tumor recurrence after initial tumor resection may be explained by a number of factors; one is tumor cell implantation. A number of small trials have suggested a reduction in tumor recurrences by instillation of chemotherapy immediately after resection. Based on these preliminary data, large prospective multicenter trials have been conducted and have confirmed the benefit of immediate adjuvant intravesical chemotherapy. Bacillus Calmette-Guerin (BCG) cannot be administered immediately postresection because of the potential for systemic dissemination via the recently resected tumor bed. Therefore, combination strategies using immediate instillation of a cytotoxic agent followed by BCG induction and maintenance presents an attractive strategy that is currently under study and one that may be more commonly employed in the future treatment of patients with superficial transitional cell carcinoma of the bladder.