title: Possible pro-carcinogenic association of endotoxin on lung cancer among Shanghai women textile workers.
abstract: 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.
authors.affiliation: Department of Family and Preventive Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
authors.forename: H
authors.initials: H
authors.lastname: Checkoway
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
authors.forename: J I
authors.initials: JI
authors.lastname: Lundin
authors.affiliation: Department of Environmental Health Sciences, University of California, Berkeley, CA 94720, USA.
authors.forename: S
authors.initials: S
authors.lastname: Costello
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
authors.forename: R
authors.initials: R
authors.lastname: Ray
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
authors.forename: W
authors.initials: W
authors.lastname: Li
authors.affiliation: Department of Environmental Health Sciences, University of California, Berkeley, CA 94720, USA.
authors.forename: E A
authors.initials: EA
authors.lastname: Eisen
authors.affiliation: School of Population and Public Health, University of British Columbia, Vancouver, BC V6T1Z4, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Astrakianakis
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98195, USA.
authors.forename: N
authors.initials: N
authors.lastname: Seixas
authors.affiliation: Department of Environmental and Occupational Health, George Washington University, Washington, DC 20052, USA.
authors.forename: K
authors.initials: K
authors.lastname: Applebaum
authors.affiliation: Zhong Shan Hospital Cancer Center, Shanghai 200030, China.
authors.forename: D L
authors.initials: DL
authors.lastname: Gao
authors.affiliation: Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
authors.forename: D B
authors.initials: DB
authors.lastname: Thomas
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000393:Air Pollutants / Q000633:toxicity*; D063646:Carcinogenesis / Q000139:chemically induced; D016022:Case-Control Studies; D032561:Cotton Fiber; D004391:Dust; D005260:Female; D006801:Humans; D008070:Lipopolysaccharides / Q000633:toxicity*; D008175:Lung Neoplasms / Q000139:chemically induced*; D008875:Middle Aged; D009784:Occupational Diseases / Q000139:chemically induced*; D016273:Occupational Exposure; D016016:Proportional Hazards Models; D012307:Risk Factors
chemical_list: D000393:Air Pollutants; D004391:Dust; D008070:Lipopolysaccharides