Possible pro-carcinogenic association of endotoxin on lung cancer among Shanghai women textile workers

• Published in: British journal of cancer Vol. 111; no. 3; pp. 603 - 607
• Main Authors: Checkoway, H, Lundin, J I, Costello, S, Ray, R, Li, W, Eisen, E A, Astrakianakis, G, Seixas, N, Applebaum, K, Gao, D L, Thomas, D B
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.07.2014; Nature Publishing Group
• Subjects: 692/699/67/1612; 692/699/67/2324; 692/700/3160; Aged; Aged, 80 and over; Air Pollutants - toxicity; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cancer Research; Carcinogenesis - chemically induced; Case-Control Studies; Cotton Fiber; Drug Resistance; Dust; Epidemiology; Female; Humans; Lipopolysaccharides - toxicity; Lung cancer; Lung Neoplasms - chemically induced; Medical sciences; Middle Aged; Molecular Medicine; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Occupational Diseases - chemically induced; Occupational Exposure; Oncology; Pneumology; Proportional Hazards Models; Risk Factors; Tumors; Tumors of the respiratory system and mediastinum; China, People's Rep., Shanghai; China, People's Rep; lung cancer; epidemiology; textile industry; lipopolysaccharide; occupational health; endotoxin; Human; Lung disease; Textile; Respiratory disease; Lung cancer; Malignant tumor; Endotoxin; Epidemiology; Toxin; Carcinogen; Association; Cancerology; Lipopolysaccharide; Bronchus disease; Adult; Female; Worker; Woman; Textile industry; Occupational medicine; Cancer
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.2014.308

Background: Endotoxin (lipopolysaccharide) is a widespread contaminant in many environmental settings. Since the 1970s, there has been generally consistent evidence indicating reduced risks for lung cancer associated with occupational endotoxin exposure. Methods: We updated a case–cohort study nested within a cohort of 267 400 female textile workers in Shanghai, China. We compared exposure histories of 1456 incident lung cancers cases diagnosed during 1989–2006 with those of a reference subcohort of 3022 workers who were free of lung cancer at the end of follow-up. We applied Cox proportional hazards modelling to estimate exposure–response trends, adjusted for age and smoking, for cumulative exposures lagged by 0, 10, and 20 years, and separately for time windows of ⩽15 and >15 years since first exposure. Results: We observed no associations between cumulative exposure and lung cancer, irrespective of lag interval. In contrast, analyses by exposure time windows revealed modestly elevated, but not statistically significant relative risks (∼1.27) at the highest three exposure quintiles for exposures that occurred >15 years since first exposure. Conclusions: The findings do not support a protective effect of endotoxin, but are suggestive of possible lung cancer promotion with increasing time since first exposure.