From epidemiology to molecular pathology: current research status and future prospects on the role of toxic metal exposure in the development and progression of bladder cancer
Year: 2026
Type: review
Abstract: Bladder cancer remains a prevalent and lethal urinary malignancy, characterized by high recurrence rates and persistently poor prognosis for muscle-invasive disease. This clinical reality underscores the urgent need to identify modifiable risk factors. Epidemiological evidence from case-control and prospective cohort studies has established dose-dependent associations with arsenic and consistent tissue-specific accumulation of cadmium and chromium, while lead remains conditional on metabolic status. Nevertheless, substantial study heterogeneity persists, largely due to differences in exposure assessment methods, dose-response patterns, and confounding by smoking. A comprehensive synthesis integrating population-level findings with mechanistic insights remains conspicuously lacking. This review addresses this gap by critically evaluating the epidemiological associations, appraising sources of heterogeneity, and synthesizing current mechanistic understanding. The evidence points to a convergent model in which these metals trigger ROS-mediated oxidative stress and mitochondrial dysfunction as upstream initiating events, which aberrantly activate two midstream signaling branches-the ROS-dependent p38-MAPK/NF-κB and PI3K/AKT pathways promoting proliferation and survival, and the ROS-independent SUMOylation/TGF-β/Smad2/3 axis driving epithelial-mesenchymal transition. NRF2 exhibits stage-dependent duality with extensive pathway crosstalk, and these signals converge on downstream outcomes, including resistance to apoptosis, invasion, and metastasis. Beyond cancer cell-intrinsic effects, emerging evidence indicates that metal-induced signaling aberrations also remodel the tumor microenvironment through immune reprogramming, stromal activation, and metabolic shifts. Based on these insights, we propose a biomarker-guided, multi-tiered prevention framework spanning primary environmental control, secondary chemoprevention, and tertiary targeted therapy. Despite encouraging progress, critical knowledge gaps persist, particularly regarding multi-metal co-exposure, population-level mechanistic validation, and clinical translation. This review identifies these limitations and charts interdisciplinary research directions that integrate advanced exposure assessment, multi-omics, and rigorous clinical evaluation to bridge environmental exposure science and precision prevention of bladder cancer.
Authors: Danrui Li, Xu Sun, Tong Yu
Language: English
Subfield: Health, Toxicology and Mutagenesis
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W7223028426