Contemporary Occupational Carcinogen Exposure and Bladder Cancer

Abstract

IMPORTANCEBladder cancer (BC) is a common disease. Despite manufacturing and legislative changes to workplace hygiene, many BCs still arise through occupational carcinogen exposure.OBJECTIVE To profile contemporary risks of occupational BC.DATA SOURCES A systematic review using PubMed, Medline, Embase, and Web of Science was performed in October 2012 (initial review) and May 2014 (final review) and was updated in June 2015.STUDY SELECTION We identified 263 eligible articles. We excluded reports in which BC or occupation were not the main focus, and those with insufficient case, risk, or confidence interval data. We selected the most recent data from populations with multiple reports.DATA EXTRACTION AND SYNTHESIS Reports were selected by 2 of us independently. We combined odds ratios and risk ratios (RRs) to provide pooled RRs, using maximally adjusted RRs in a random effects model. Heterogeneity and publication bias were assessed using I 2 and Begg and Egger tests. Risk estimates were annotated by occupational class using Nordisk Yrkesklassificering, or Nordic Occupational Classification, and International Standard Classifications of Occupations (NYK and ISCO-1958) Codes. MAIN OUTCOMES AND MEASURESOccupations were profiled by BC incidence and mortality risk over time. After data collection, we detected a sex difference in these profiles and recorded this as a secondary outcome.RESULTS Meta-analysis revealed increased BC incidence in 42 of 61 occupational classes and increased BC-specific mortality in 16 of 40 occupational classes. Reduced incidence and mortality were seen in 6 of 61 and 2 of 40 classes, respectively. Risk varied with sex and was greatest in men (standardized incidence ratio, 1.03 [95% CI, 1.02-1.03]; P < .001]). From the 1960s to the 1980s, there was a steady decline in standarized incidence ratio (SIR) for both sexes. This trend reversed from the 1980s, as in the decade 2000 to 2010 the SIR increased to 1.13 (95% CI, 1.07-1.19) for men and 1.27 (95% CI, 1.12-1.43) for women. In contrast, mortality risk declined for both sexes from the 1960s to the 1990s. The overall risk of BC mortality was also greater for men (standardized mortality ratio [SMR], 1.32 [95% CI, 1.18-1.48]) than for women (SMR, 1.14 [95% CI,). Limitations include possible publication bias, that reports stratify workers mostly by job title not task, that not all studies adjusted for smoking, and that the population was mostly derived from Western nations.CONCLUSIONS AND RELEVANCE The profile of contemporary occupations with increased BC risk is broad and differs for incidence and mortality. Currently the incidence seems to be increasing, and this increase is occurring faster in women than men. Improved detection mechanisms and screening are possible reasons for this. Workers with aromatic amine exposure have the highest incidence, while those exposed to polycyclic aromatic hydrocarbons and heavy metals have the greatest mortality.

Modifiable risk factors for the prevention of bladder cancer: a systematic review of meta-analyses

“…However, these findings will not be further discussed and repeated here as the MA by Cumberbatch et al [61] offers an interesting and elaborate discussion on the matter. They also attempted to study a change in occupational risk over time but were limited by heterogeneity and small sample sizes.…”

“…Moreover, four MAs [61–64] reported on a large number of occupational categories. Cumberbatch et al [61] and Reulen et al [62] authored two large MAs on different occupations based on 217 and 130 different studies respectively, whereas Kogevinas et al [63] and ‘t Mannetje et al [64] both did a pooled analysis of eleven case–control studies conducted in European countries reporting results for men and women, respectively. The paper by Cumberbatch et al was considered the most comprehensive for all identified occupations based on the number of studies included.…”

Bladder cancer prevention

“…naphthalene, benzo(a)pyrene), coal tar, aniline pigments (e.g. methoxyaniline, methoxy-nitroaniline), polychlorinated dibenzodioxins, dibenzofuran, and chlorinated aliphatic hydrocarbons [7,17,18]. A major role is also played by metals such as arsenic, cadmium, chromium, and nickel [18].…”

“…methoxyaniline, methoxy-nitroaniline), polychlorinated dibenzodioxins, dibenzofuran, and chlorinated aliphatic hydrocarbons [7,17,18]. A major role is also played by metals such as arsenic, cadmium, chromium, and nickel [18]. Cumberbatch et al performed a metaanalysis focused on the incidence of bladder cancer in various occupational groups; the data indicated a highly specific occupational profile of patients exposed to chemical carcinogens.…”

“…Cumberbatch et al performed a metaanalysis focused on the incidence of bladder cancer in various occupational groups; the data indicated a highly specific occupational profile of patients exposed to chemical carcinogens. The highest risk of bladder cancer is reported in individuals working with aromatic amines, while the highest mortality rate is observed in those exposed to PAHs and heavy metals [18]. Even though social awareness of the importance of workplace hygiene is growing and appropriate measures are being taken, the reduction of occupational exposure to carcinogenic compounds continues to be an important element of bladder cancer prevention.…”