Intravesical chemotherapy in non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer (NMIBC) is characterized by a tendency for recurrence and capacity for progression. Intravesical instillation therapy has been employed in various clinical settings, which are summarized within this review. Several chemotherapeutic agents have shown clinical efficacy in reducing recurrence rates in the post-transurethral resection of bladder tumor (TURBT) setting, including mitomycin C (MMC), doxorubicin, and epirubicin. Mounting evidence also supports the use of intravesical MMC following nephroureterectomy to reduce later urothelial bladder recurrence. In the adjuvant setting, bacillus Calmette-Guérin (BCG) immunotherapy is an established first-line agent in the management of carcinoma in situ (CIS) and high-grade non muscle invasive urothelial carcinoma (UC). Among high and intermediate-risk patients (based on tumor grade, size, and focality) improvements in disease-free intervals have been seen with adjunctive administration of MMC prior to scheduled BCG dosing. Following failure of first-line intravesical therapy, gemcitabine and valrubicin have demonstrated modest activity, though valrubicin remains the only agent currently Food and Drug Administration (FDA)-approved for the treatment of BCG-refractory CIS. Techniques to optimize intravesical chemotherapy delivery have also been explored including pharmacokinetic methods such as urinary alkalization and voluntary dehydration. Chemohyperthermia and electromotive instillation have been associated with improved freedom from recurrence intervals but may be associated with increased urinary toxicity. Improvements in therapeutic selection may be heralded by novel opportunities for genomic profiling and refinements in clinical risk stratification.