The contemporary landscape of occupational bladder cancer within the United Kingdom: a meta-analysis of risks over the last 80 years

Objective To profile the contemporary risks of occupational bladder in the UK, as this is a common malignancy that arises through occupational carcinogen exposure. Materials and methods A systematic review using PubMed, Medline, Embase and Web of Science was performed in March 2016. We selected reports of British workers in which bladder cancer or occupation were the main focus, with sufficient cases or with confidence intervals (CIs). We used the most recent data in populations with multiple reports. We combined odds ratios and risk ratios (RRs) to provide pooled RRs of incidence and disease-specific mortality (DSM). We tested for heterogeneity and publication bias. We extracted bladder cancer mortality from Office of National Statistics death certificates. We compered across regions and with our meta-analysis. Results We identified 25 articles reporting risks in 702 941 persons. Meta-analysis revealed significantly increased incidence for 12/37 and DSM for five of 37 occupational classes. Three classes had reduced bladder cancer risks. The greatest risk of bladder cancer incidence occurred in chemical process (RR 1.87, 95% CI 1.50-2.34), rubber (RR 1.82, 95% CI 1.4-2.38), and dye workers (RR 1.8, 95% CI 1.07-3.04). The greatest risk of DSM occurred in electrical (RR 1.49, 95% CI 1.19-1.87) and chemical process workers (RR 1.35, 95% CI 1.09-1.68). Bladder cancer mortality was higher in the North of England, probably reflecting smoking patterns and certain industries. Limitations include the lack of sufficient robust data, missing occupational tasks, and no adjustment for smoking. Conclusion Occupational bladder cancer occurs in many workplaces and the risks for incidence and DSM may differ. Regional differences may reflect changes in industry and smoking patterns. Relatively little is known about bladder cancer within British industry, suggesting official data underestimate the disease.