Occupational exposures and ovarian cancer in textile workers.
BACKGROUND
Occupational risk factors for ovarian cancer have been investigated only to a limited extent. We conducted a case-cohort study to examine associations between occupational exposures and ovarian cancer in the textile industry.


METHODS
We compared 261 incident ovarian cancer cases diagnosed between 1989 and 1998 with an age-stratified reference subcohort (n = 3199) from a cohort of 267,400 textile workers in Shanghai, China. Occupational exposures were assessed by job-exposure matrices designed for the textile industry, and estimates of quantitative cotton dust and endotoxin. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) with Cox proportional hazards modeling adapted for the case-cohort design.


RESULTS
A decreased risk of ovarian cancer was associated with ever having worked in cotton manufacturing production (HR = 0.7; 95% CI = 0.4-1.0). An increased risk was associated with ever having worked in textile finishing (2.1; 0.9-5.0). We found an increasing risk of ovarian cancer associated with cumulative exposure to silica dust (for <10 years exposure, HR = 6.8 [CI = 0.6-76]; for > or =10 years, 5.6 [1.3-23.6]), although these results are based on only 8 exposed subcohort women (0.3%) and 4 cases (1.3%). We also detected inverse risk gradients for cumulative exposures to endotoxin when exposures were lagged by 20 years (in highest quartile, HR = 0.6 [CI = 0.4-1.1]).


CONCLUSIONS
Silica dust may increase the risk of ovarian cancer, and cotton dust and endotoxin may reduce risk.
Wernli
Karen J
KJ
Program in Epidemiology, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA. kwernli@fhcrc.org
Ray
Roberta M
RM
Gao
Dao Li
DL
Fitzgibbons
E Dawn
ED
Camp
Janice E
JE
Astrakianakis
George
G
Seixas
Noah
N
Wong
Eva Y
EY
Li
Wenjin
W
De Roos
Anneclaire J
AJ
Feng
Ziding
Z
Thomas
David B
DB
Checkoway
Harvey
H
D000328:Adult; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D032561:Cotton Fiber; D004391:Dust / Q000032:analysis; D004731:Endotoxins / Q000633:toxicity; D005260:Female; D006090:Gram-Negative Bacteria; D006801:Humans; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D010051:Ovarian Neoplasms / Q000453:epidemiology* / Q000209:etiology* / Q000517:prevention & control; D016016:Proportional Hazards Models; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012822:Silicon Dioxide / Q000633:toxicity; D013783:Textile Industry; D013997:Time Factors
D004391:Dust; D004731:Endotoxins; D012822:Silicon Dioxide