The Impact of Immune Checkpoint-Inhibitors Therapy in Urinary Bladder Cancer

Abstract

Bladder cancer (BC) is one of the most common cancers in the world. From an early age, it was observed that chronic inflammation is associated with conditions favorable to the development of tumors, as well as the tumor microenvironment. Moreover, regulating tumor progression also interferes with the therapy’s response. The interaction between the tumor and the immune system led to the development of new immune therapies, the immune checkpoint inhibitors. Immunotherapy has shown a better safety profile, survival, and tolerance compared to standard chemotherapy. This therapy offers an effective alternative to patients who are ineligible for cisplatin and patients with advanced disease progression after platinum-based therapy. The first immunotherapy approved for BC was intravesical instillation with Bacillus Calmette–Guérin, for tumors at early stages. Later, immunotherapy focused on immune checkpoint inhibitors, namely, anti-programmed cell death protein 1 (PD1), anti-programmed cell death protein ligand 1(PD-L1), and anti-antigen 4 associated with cytotoxic T cells (CTLA-4). Currently, five immune checkpoint inhibitors for advanced BC are approved by the Food and Drug Administration (FDA): Atezolizumab, Durvalumab, Avelumab, Pembrolizumab, and Nivolumab. This review addresses the correlation between inflammation, tumor microenvironment, and cancer; various studies regarding immune checkpoint inhibitors, either in monotherapy or in combination therapy, are also addressed.