Occupation and breast cancer risk among Shanghai women in a population-based cohort study.
BACKGROUND
A total of 74,942 female subjects were recruited in a population-based cohort study in Shanghai, China between 1997 and 2000. We examined the relationship between occupation and breast cancer risk.


METHODS
Cases were 586 women previously diagnosed with breast cancer at baseline and 438 women newly diagnosed with breast cancer during follow-up through December 2004. Eight controls were randomly selected for each case from cancer-free cohort members and frequency-matched to the cases by year of birth and age at diagnosis. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) of breast cancer risk associated with occupations, adjusting for established breast cancer risk factors.


RESULTS
In the prevalent breast cancer data analysis, increased risks of breast cancer were associated with technicians in engineering/agriculture/forestry (OR = 1.6, CI: 1.0-2.4), teaching personnel (OR = 1.5, CI:1.1-2.0), tailoring/sewing workers (OR = 1.6, CI:1.0-2.7), and examiners/measurers/testers (OR = 1.5, CI:1.1-2.1) among those who started the jobs at least 20 years ago. Among incident breast cancer cases, significantly increased risks were associated with medical/health care workers (OR = 1.4, CI:1.0-2.0), administrative clerical workers (OR = 1.5, CI:1.0-2.4), postal/telecommunication workers (OR = 2.2, CI:1.0-5.5), and odd-job workers (OR = 1.7, CI:1.1-2.8) among those who started the jobs at least 20 years ago. The excess risks were found in both prevalent and incident cases for postal/telecommunication workers and purchasing/marketing personnel, although ORs reached only marginal significance.


CONCLUSIONS
This study suggests that white-collar professionals and several production occupations may be associated with an increased risk of breast cancer.
Ji
Bu-Tian
BT
National Cancer Institute, NIH, DHHS, Bethesda, Maryland 20852, USA. jib@exchange.nih.gov
Blair
Aaron
A
Shu
Xiao-Ou
XO
Chow
Wong-Ho
WH
Hauptmann
Michael
M
Dosemeci
Mustafa
M
Yang
Gong
G
Lubin
Jay
J
Gao
Yu-Tang
YT
Rothman
Nathaniel
N
Zheng
Wei
W
D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000453:epidemiology*; D016022:Case-Control Studies; D002681:China / Q000453:epidemiology; D005260:Female; D006306:Health Surveys; D006801:Humans; D015994:Incidence; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology*; D016273:Occupational Exposure / Q000009:adverse effects*; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors; D011795:Surveys and Questionnaires; D016387:Women's Health