Occupations and breast cancer risk among Chinese women in urban Shanghai.
BACKGROUND
Although, an elevated risk of breast cancer has been suggested for a number of occupations, many earlier studies were limited by selection biases, the incomplete assessment of job histories, and the inability to control for confounding.


METHODS
We examined the relationship between occupational history and breast cancer risk using data from a population-based case-control study of 1,458 cases and 1,556 age-matched controls (90% response rate) conducted in Shanghai, China. Unconditional logistic regression models were used to derive odds ratios (ORs) and 95% confidence intervals (95% CIs) of breast cancer risk associated with occupations and duration of employment adjusting for non-occupational risk factors.


RESULTS
The following occupations were found to be associated with an increased risk of breast cancer: laboratory technicians (OR 9.94, 95% CI 1.20-82.37), telephone and telegraph operators (OR 4.63, 95% CI 1.85-11.59), leather and fur processors (OR 3.25, 95% CI 1.11-9.53), and glass-manufacturing workers (OR 2.08, 95% CI 1.14-3.82). A dose-response pattern for years of employment was observed for leather and fur processors (P = 0.02) and glass-manufacturing workers (P = 0.01). Stratified analyses also revealed dose-response relationships between the risk of breast cancer and years of employment as inspector and product analysts among pre-menopausal women (P = 0.02), and as farmers among post-menopausal women (P = 0.04).


CONCLUSIONS
This study found that several occupations are associated with an increased risk of breast cancer among women. Studies examining various occupational exposures in these high-risk occupations are warranted to identify carcinogens that may play a role in the increased breast cancer risk.
Gardner
Kathleen M
KM
Department of Medicine, and Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37232-8300, USA.
Ou Shu
Xiao
X
Jin
Fan
F
Dai
Qi
Q
Ruan
Zhixian
Z
Thompson
Shirley J
SJ
Hussey
James R
JR
Gao
Yu Tang
YT
Zheng
Wei
W
D000328:Adult; D000886:Anthropometry; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D016273:Occupational Exposure; D009790:Occupations; D016017:Odds Ratio; D012307:Risk Factors; D014505:Urban Population