Occupational exposures and risk of oesophageal cancer by histological type: a case-control study in eastern Spain

Our plain-English summary of Occupational exposures and risk of oesophageal cancer by histological type: a case-control study in eastern Spain, by M. Santibañez, J. Vioque, J. Alguacil, et al (Occupational and Environmental Medicine, 2008).

The study

• Authors: M. Santibañez, J. Vioque, J. Alguacil, X. Barber, M. García de la Hera, T. Kauppinen, PANESOES Study Group
• Journal: Occupational and Environmental Medicine
• Published: 2008;65(11):774-81
• Cited by: 39 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: To explore the relationship between occupations and specific occupational exposures and oesophageal cancer (OC) by histological type.

Methods: A multicentre hospital-based case-control study was conducted in two Mediterranean provinces of Spain. Occupational, sociodemographic and lifestyle information was collected from 185 newly diagnosed male oesophageal cancer patients (147 squamous cell, 38 adenocarcinoma) and 285 frequency matched controls. Occupation was coded according to the Spanish National Classification of Occupations 1994. Occupational exposure to a selection of carcinogenic substances was assessed by the FINJEM job exposure matrix. Odds ratios were calculated by unconditional logistic regression adjusting for age, education, alcohol intake and cigarette smoking.

Results: For the squamous cell variety, statistically significant associations were found for waiters and bartenders (OR 8.18, 95% CI 1.98 to 33.75) and miners, shotfirers, stone cutters and carvers (OR 10.78, 95% CI 1.24 to 93.7) in relation to other occupations. For the adenocarcinoma variety, statistically significant associations were observed for carpenters and joiners (OR 9.69), animal producers and related workers (OR 5.61) and building and related electricians (OR 8.26), although these observations were based on a low number of cases. Regarding specific exposures, the study found a statistically significant increased risk of squamous cell carcinoma for ionising radiation, and of adenocarcinoma for high exposure to volatile sulphur compounds (OR 3.12) and lead (OR 5.30). For all histological types of OC combined, a three-fold increase in risk was found with a significant trend for asbestos exposure (OR 3.46, 95% CI 0.99 to 12.10).

Conclusions: The data suggest that some occupational exposures may specifically increase the risk of oesophageal squamous cell carcinoma or adenocarcinoma, while other exposures such as asbestos may increase the overall risk of OC.

In plain English

This hospital-based case-control study, part of the PANESOES project, compared 185 men newly diagnosed with oesophageal cancer (145 squamous cell carcinoma, 38 adenocarcinoma) with 285 male hospital controls in Alicante and Valencia, Spain, between 1995 and 1999. Job histories came from interviews. Exposure to asbestos and other agents was estimated with a Finnish job exposure matrix (FINJEM), and the article does not name asbestos fibre types. Results were adjusted for age, province, education, alcohol and smoking. For all oesophageal cancers combined, the high asbestos category (8 cases, 7 controls) had an odds ratio of 3.46 (95% CI 0.99 to 12.10; trend p = 0.07). Low exposure gave 1.27 (0.77 to 2.10). Similar estimates for each cancer type separately were not statistically significant. Waiters and bartenders, and miners, shotfirers, stone cutters and carvers, had raised odds of squamous cell carcinoma. The authors concluded that asbestos may increase overall oesophageal cancer risk. They noted that FINJEM was not adapted to Spain and may have overestimated asbestos exposure, and that many comparisons and small numbers mean some findings may be due to chance.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Multicentre hospital-based case-control study (part of the PANESOES project), analysed by unconditional logistic regression
• Who was studied: 185 men newly diagnosed with primary invasive oesophageal cancer, histologically confirmed, and 285 male hospital controls with conditions such as hernias and fractures. Patients were in nine hospitals in the provinces of Alicante and Valencia, Spain, hospitalised January 1995 to March 1999. The methods and tables give 145 squamous cell carcinomas and 38 adenocarcinomas.
• Exposure: The two main lifetime occupations were coded by job title. Exposure to 21 chemical agents (including asbestos), four physical agents and two ergonomic factors was estimated with the FINJEM job exposure matrix and classed as unexposed, low or high. For asbestos, high meant above 0.26 fibres per cubic centimetre. No fibre type was specified.
• Main results:
  • All oesophageal cancers combined, high asbestos exposure (8 exposed cases, 7 exposed controls): odds ratio 3.46 (95% CI 0.99 to 12.10), p for trend 0.07. Low asbestos exposure (60 cases, 69 controls): odds ratio 1.27 (95% CI 0.77 to 2.10).
  • High asbestos exposure, by cancer type, not statistically significant. Squamous cell carcinoma: odds ratio 3.42 (95% CI 0.76 to 15.34). Adenocarcinoma: odds ratio 3.99 (95% CI 0.67 to 23.77).
  • Asbestos was the most common FINJEM-identified exposure among cases (68 cases). The highly exposed cases worked as carpenters and joiners (4), miners and quarry workers (3) and manufacturing labourers (1).
  • Squamous cell carcinoma: waiters and bartenders had an odds ratio of 8.18 (95% CI 1.98 to 33.75). Miners, shotfirers, stone cutters and carvers had an odds ratio of 10.78 (95% CI 1.24 to 93.65).
  • Adenocarcinoma: carpenters and joiners had an odds ratio of 9.69 (95% CI 1.32 to 70.81), animal producers 5.61 (95% CI 1.13 to 27.74), and building and related electricians 8.26 (95% CI 1.06 to 64.22). These were based on few cases.
• The authors' conclusion: The authors concluded that some occupations may specifically increase the risk of squamous cell carcinoma or adenocarcinoma of the oesophagus, while some exposures such as asbestos may increase the overall risk of oesophageal cancer. They called for further research to confirm the results.
• Limitations the authors state:
  • FINJEM exposure estimates were not adapted to Spanish conditions.
  • The authors said FINJEM may have overestimated asbestos exposure in Spanish subjects, because Spain had no asbestos mines and probably used less asbestos in construction. They argued that any such misclassification would be non-differential, so the true asbestos effect could be stronger.
  • Many comparisons were made without correction for multiple testing, so some associations may be false positives due to chance.
  • Some associations rested on small numbers of exposed subjects.
  • Only the two main occupations per person were recorded, not the full lifetime job history.
  • Case-control studies may not be the best design for studying occupational exposures, especially uncommon ones.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Throat and laryngeal cancer.

Medical terms in this study, explained in our Lexicon: Occupational Exposure, Esophageal Cancer, Case-Control Study, Squamous Cell Carcinoma, Adenocarcinoma, Carcinogenic, Odds Ratio, Asbestos Exposure.

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• Occupational asbestos exposure and risk of esophageal, gastric and colorectal cancer in the prospective Netherlands Cohort Study — N.S. Offermans, R. Vermeulen, et al. (2014)
• Occupational exposures and risk of esophageal and gastric cardia cancers among male Swedish construction workers — C. Jansson, A.L. Johansson, et al. (2005)
• A case-control study on occupational lung cancer risks in an industrialized city of Japan — N. Yamaguchi, M. Kido, et al. (1992)
• Ingested asbestos in filtered beer, in addition to occupational exposure, as a causative factor in oesophageal adenocarcinoma — R.C. Fitzgerald, J.M. Rhodes (2019)

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