Immunotherapy of renal and bladder cancers

Abstract

Bladder urothelial carcinoma accounts for about 5 % of all cancer deaths in humans; in addition, it is associated with a significantly high mortality rate. The efficacy of immunotherapy in the treatment of both renal and bladder cancer is variable. Immunotherapy with Bacillus Calmette–Guérin (BCG) has become a first-line treatment in high-grade, nonmuscle, invasive bladder cancer (NMIBC). In addition, BCG reduces the risk of progression in high-risk NMIBC. It has been established as the most effective adjuvant treatment for preventing local recurrence and tumor progression, following transurethral resection (TUR) of NMIBCs. Nonetheless, it is associated with some mainly mild or moderate side effects, such as cystitis (67 %), hematuria (23 %), moderate fever (25 %), and high and increased urinary frequency. The immune response to mycobacteria is related to the response of antigen-presenting cells (monocytes, macrophages, dendritic cells [DCs]) to the infection and is associated with the production of cytokines, such as IFN, IL-12, and IL-15. On the other hand, the tumor develops some resistance mechanisms, including to treatment with BCG, allowing it to escape immune host surveillance. Therefore, the optimal BCG treatment scheme remains to be defined. Indeed, many protocols have been proposed. New indications for cytoreductive surgery in patients with metastatic renal cell cancer have been provided by immunotherapy. Recently, immunotherapeutic approaches involving cytokines have been employed in the treatment of metastasized kidney cancer, which may either be in the form of monokines (such as tumor necrosis factor or interleukin-1), or lymphokines (such as interferon and interleukin 2). They can also be used in synergistic associations with certain chemotherapeutics, including vinblastine, 5-fluorouracil, and mitomycin or VP16. Finally, immunotherapy has significantly improved the outcome in patients with bladder and renal cancer. Nonetheless, more studies are warranted.