A systematic review on the available treatment modalities for Bacillus Calmette-Guérin-unresponsive carcinoma in situ and tumors in patients who are ineligible for or decline radical cystectomy

Introduction: Globally, urothelial bladder carcinoma is a disease which carries a poor prognosis. There are various treatment modalities for urothelial bladder carcinoma with intravesical Bacillus Calmette-Guérin immunotherapy being the most efficacious intravesical therapy and the treatment of choice for patients with carcinoma in situ. A number of chemotherapeutic drugs are also available for the management of Ta/T1 tumors such as mitomycin C and epirubicin. However, relapse and progression is quite common. The optimal management of patients with Bacillus Calmette-Guérin-unresponsive disease remains to be a challenge. The purpose of this study was to conduct a systematic review on the treatment modalities available for the management of Bacillus Calmette-Guérin-unresponsive carcinoma in situ and urothelial bladder carcinoma in patients who are ineligible or decline radical cystectomy.

Methods: Two authors independently searched three databases on the treatment modalities available for the management of Bacillus Calmette-Guérin-unresponsive carcinoma in situ and Bacillus Calmette-Guérin-unresponsive urothelial bladder carcinoma.

Results: The systematic search resulted in 15 studies. We recommend the use of intravesical CG0070 adenovirus or hyperthermic intravesical chemotherapy mitomycin C in patients with carcinoma in situ only disease. In patients with carcinoma in situ ± Ta/T1 disease, we recommend the use of intravesical radiofrequency-induced chemohyperthermia or electromotive drug administration of mitomycin C. In patients who have Ta/T1 disease, we recommend the use of either hyperthermic intravesical chemotherapy epirubicin or electromotive drug administration mitomycin C followed by chemohyperthermia mitomycin C. If any of these second line therapies fail, an alternative regimen would be a combination of gemcitabine, cabazitaxel, and cisplatin.

Conclusion: This recommendation is subject to the available resources and clinical expertise available in different hospitals. More studies using study designs such as randomized controlled trials comparing multiple drugs with larger sample sizes and regular follow-up intervals should be performed to accurately assess the different medications and aid in designing guidelines to guide the management of Bacillus Calmette-Guérin-unresponsive non-muscle invasive intravesical bladder cancer.