Occupational exposure to petroleum-based and oxygenated solvents and oral and oropharyngeal cancer risk in men: A population-based case-control study in France.

OBJECTIVE: To examine the association between occupational exposure to petroleum-based and oxygenated solvents and the risk of oral and oropharyngeal cancer. METHODS: The ICARE study is a large population-based case-control study conducted in France between 2001 and 2007. This present analysis was restricted to men and included 350 and 543 cases of squamous cell-carcinoma of the oral cavity and oropharynx, respectively, and 2780 controls. Lifetime tobacco, alcohol consumption and complete occupational history were assessed through detailed questionnaires. Job-exposure matrices allowed us to assess occupational exposure to five petroleum-based solvents (white spirits; diesel/fuel oils/kerosene; gasoline; benzene; special petroleum products) and five oxygenated solvents (diethyl ether; tetrahydrofuran; ketones and esters; alcohols; ethylene glycol). Odds-ratios (ORs), adjusted for age, smoking, alcohol consumption and socioeconomic status, and 95% confidence intervals (CI) were estimated using unconditional logistic models. RESULTS: Associations between oral cancer risk and exposure to white spirits and diesel/fuel oils/kerosene were suggested, but there was no exposure-response trend. Concerning exposure to oxygenated solvents, participants with the highest levels of cumulative exposure to diethyl ether had a significant excess risk of oropharyngeal cancer (OR = 7.78, 95%CI 1.42 to 42.59; p for trend = 0.04). Ever exposure to tetrahydrofuran was associated with a borderline significant increased risk of oral cancer (OR = 1.87, 95%CI 0.97 to 3.61), but no exposure-response trend was observed. Additional adjustments for exposure to other solvents did not substantially change the results. CONCLUSION: Our results do not provide evidence for a major role of petroleum-based and oxygenated solvents in the occurrence of oral and oropharyngeal cancers in men.

Occupational exposure to petroleum-based and oxygenated solvents and hypopharyngeal and laryngeal cancer in France: the ICARE study.

BACKGROUND: To examine associations between occupational exposure to petroleum-based and oxygenated solvents and the risk of hypopharyngeal and laryngeal cancer. METHODS: ICARE is a large, frequency-matched population-based case-control study conducted in France. Lifetime occupational history, tobacco smoking and alcohol consumption were collected. Analyses were restricted to men and included 383 cases of hypopharyngeal cancer, 454 cases of laryngeal cancer, and 2780 controls. Job-exposure matrices were used to assess exposure to five petroleum-based solvents (benzene; gasoline; white spirits; diesel, fuels and kerosene; special petroleum products) and to five oxygenated solvents (alcohols; ketones and esters; ethylene glycol; diethyl ether; tetrahydrofuran). Odds ratios (ORs) adjusted for smoking, alcohol drinking and other potential confounders and 95% confidence intervals (CI) were estimated with unconditional logistic models. RESULTS: No significant association was found between hypopharyngeal or laryngeal cancer risk and exposure to the solvents under study. Non-significantly elevated risks of hypopharyngeal cancer were found in men exposed to high cumulative levels of white spirits (OR = 1.46; 95% CI: 0.88-2.43) and tetrahydrofuran (OR = 2.63; 95CI%: 0.55-12.65), with some indication of a dose-response relationship (p for trend: 0.09 and 0.07 respectively). CONCLUSION: This study provides weak evidence for an association between hypopharyngeal cancer and exposure to white spirits and tetrahydrofuran, and overall does not suggest a substantial role of exposure to petroleum-based or oxygenated solvents in hypopharyngeal or laryngeal cancer risk.

Tea and coffee consumption and risk of oral cavity cancer: results of a large population-based case-control study, the ICARE study.

BACKGROUND: Results on the relationship between coffee and tea drinking and the risk of oral cavity cancer are contrasted. The aim of this study was to evaluate the relation between coffee and tea drinking and the risk of oral cavity cancer in France, a high incidence area. MATERIAL AND METHODS: We conducted a population based case-control study with face-to-face interviews and standardized questionnaires (the ICARE study, Investigation of occupational and environmental causes of respiratory cancers). We used data from 689 cases of oral cavity squamous cell carcinoma and 3481 controls. Odds-ratios (ORs) and 95% confidence intervals (95% CI) associated with tea and coffee consumption (quantity, duration, cumulative consumption) were estimated by unconditional logistic regression with adjustment for age, gender, area of residence, education, body mass index, tobacco smoking and alcohol drinking. RESULTS: We observed inverse associations between oral cavity cancer and tea or coffee consumption (odds ratio, 0.39; 95% CI 0.21-0.70, for the highest quartile of tea consumption, and 0.60, 95% CI 0.34-1.05, for the highest quartile of coffee consumption). Exclusive tea or coffee consumption was associated with a reduced risk of oral cavity cancer and their joint effect was multiplicative. No differences in risk between men and women or between consumers of tobacco and alcohol and non-consumers were observed. The odds ratios related to the subsites usually included in the oropharynx (soft palate and base of the tongue) did not differ significantly from that observed for the other subsites of the oral cavity. CONCLUSIONS: Tea and coffee drinking may decrease the risk of oral cavity cancer through antioxidant components which play a role in the repair of cellular damages. These findings need further investigation in prospective studies and the underlying mechanisms in humans remain to be clarified.