Occupational exposures and colorectal cancers: A quantitative overview of epidemiological evidence

Abstract

A traditional belief widespread across the biomedical community was that dietary habits and genetic predisposition were the basic factors causing colorectal cancer. In more recent times, however, a growing evidence has shown that other determinants can be very important in increasing (or reducing) incidence of this malignancy. The hypothesis that environmental and occupational risk factors are associated with colorectal cancer is gaining ground, and high risks of colorectal cancer have been reported among workers in some industrial branches. The aim of this study was to investigate the epidemiologic relationship between colorectal cancer and occupational exposures to several industrial activities, by means of a scientific literature review and meta-analysis. This work pointed out increased risks of colorectal cancer for labourers occupied in industries with a wide use of chemical compounds, such as leather (RR = 1.70, 95%CI: 1.24-2.34), basic metals (RR = 1.32, 95%CI: 1.07-1.65), plastic and rubber manufacturing (RR = 1.30, 95%CI: 0.98-1.71 and RR = 1.27, 95%CI: 0.92-1.76, respectively), besides workers in the sector of repair and installation of machinery exposed to asbestos (RR = 1.40, 95%CI: 1.07-1.84). Based on our results, the estimated crude excess risk fraction attributable to occupational exposure ranged from about 11% to about 15%. However, homogeneous pattern of association between colorectal cancer and industrial branches did not emerge from this review.

Case–control study to assess the association between colorectal cancer and selected occupational agents using INTEROCC job exposure matrix

“…These agents were selected for analysis because of their probable association with colorectal cancer, based on previous research 7. We categorised the agents into five groups: solvents (toluene, aromatic hydrocarbon solvents, methylene chloride, aliphatic and alicyclic hydrocarbon solvents); combustion products (diesel exhaust emissions, gasoline exhaust emissions, benzo(a)pyrene, polycyclic aromatic hydrocarbons, welding fumes); metals (chromium, iron, nickel, lead); dusts (animal dust, asbestos, quartz, wood dust); and other (formaldehyde).…”

“…The studies that have been done have found associations between colorectal cancer risk and different occupational groups such as textile industry workers, firefighters, automobile workers,7 petrochemical industry workers,8 beverage industry workers, iron and steel workers, dockyard workers9–11 and railway employees 12. Most of these studies described the association with job categories rather than occupational agents.…”

The effect of metallothionein 2A core promoter region single-nucleotide polymorphism on accumulation of toxic metals in sinonasal inverted papilloma tissues

“…Unfortunately, the results of studies concerning the associations between the level of toxic metals and metallic agents with either pathological tumor features and disease outcome or cancer risk, have been contradictory, and no firm conclusions can be drawn from them (Basu et al, 2013;Oddone et al, 2014;Park et al, 2012;Sivulka and Seilkop, 2009). Moreover, a literature survey reveals only individual studies related to these parameters in head and neck region neoplasms and none to sinonasal inverted papilloma (Akinmoladun et al, 2013;Kosova et al, 2012;Starska et al, 2014a).…”

“…Exposure to these inorganics in the form of free ions, metal complexes, metal particles and poorly-soluble compounds occurs most often during inhalation from environmental and occupational sources at workplaces and through ingestion. Metal toxicity in humans may also be related to iatrogenic or genetic factors (Crisponi, 2014;Oddone et al, 2014;Tokar et al, 2011).…”

Increasing deaths from colorectal cancer in Poland – Insights for optimising colorectal cancer screening in society and space

“…An inverse relationship between fish consumption and colorectal cancer was found in most previous studies [29], whereas the relationship between red meat consumption and colorectal cancer remains a subject of scientific debate. This association is possibly weak in magnitude and heterogeneous across the subgroup analyses [30]. Obesity is linked with an increased risk of colon cancer in men; however, the association is less consistent in women [31].…”