Device-assisted intravesical therapy for non-muscle invasive bladder cancer

Non-muscle invasive bladder cancer (NMIBC) is a challenging disease, with a high risk of recurrence and even progression to muscle invasive disease. The present standard treatment is suboptimal, and consists of a complete transurethral resection of the visible bladder tumour(s), followed by prophylactic intravesical instillations mitomycin-C (MMC) or bacillus Calmette-Guérin (BCG). In search for higher efficacy, several adjuvant device-assisted intravesical therapies are developed. Chemohyperthermia may be based on microwave-/radiofrequency-induced (RF) hyperthermia systems, for which most evidence exists, or on hyperthermic intravesical chemotherapy, which is applied by conductive or loco-regional heating systems. RF-induced CHT has shown superiority over MMC alone, and in one prospective study superiority over BCG in per-protocol analysis, which has led to the 'weak' recommendation in the EAU guidelines to consider RF-based CHT as a bladder preservation strategy in patients with BCG-refractory tumours, who are not candidates for radical cystectomy due to comorbidities. Prospective studies on hyperthermic intravesical chemotherapy for patients with intermediate-risk NMIBC are awaited next year. The combination of electromotive drug administration (EMDA) with MMC has shown superiority over MMC as well, and seems promising when combined with BCG in sequential treatment. Photodynamic therapy should still be considered experimental, in which a study with the intravenous photosensitizer Radachlorin^® has shown promising results.