Type 2 Diabetes Mellitus and bladder cancer: A narrative review on associated signaling pathways

Bladder cancer is one of the most common cancers globally. The risk factors for urothelial bladder cancer can be broadly divided into genetic predispositions and external environmental exposures. Type 2 Diabetes Mellitus (T2DM) is a chronic, non-communicable metabolic disorder, and the interaction between genetic, behavioral, and environmental factors plays a significant role in its development. The management of T2DM includes lifestyle modifications and medication. Several studies suggest that T2DM is associated with an increased risk of bladder cancer. This review highlights the key signaling mechanisms involved in this association and explores the impact of T2DM medications on bladder cancer. In conclusion, the literature suggests that metabolic abnormalities associated with T2DM -such as hyperglycemia, insulin resistance and elevated levels of insulin, insulin-like growth factor 1 (IGF-1), inflammatory cytokines, iNOS/eNOS activity, hypoxia, dyslipidemia, matrix metalloproteinase (MMPs), leptin, vimentin, N-cadherin, fibronectin, advanced glycation end products (AGEs), endoplasmic reticulum stress (ERS), and Arntl2 gene expression; in addition to reduced E-cadherin, adiponectin, autophagy, and IGF-1 and Usp2 gene expression-significantly influence signaling pathways essential for bladder tumor development. Additionally, the choice of hypoglycemic treatment should be carefully considered, taking into account potential effects on carcinogenesis.