Environment and Breast Cancer: Science Review

Occupations and breast cancer risk among Chinese women in urban Shanghai
Gardner, K. M., Ou Shu, X., Jin, F., Dai, Q., Ruan, Z., Thompson, S. J., Hussey, J. R., Gao, Y. T., Zheng, W. Am J Ind Med. 2002. 42:4, 296-308.

Topic area
Environmental pollutant - Occupation, organic solvent
Environmental pollutant - Occupation, organic solvent
Study design
Population based case-control
Population based case-control

Study Participants
Number of Cases
1458
1458
Menopausal Status
Post menopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost menopausal
Number of Controls
Controls: 1557
Controls: 1557
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Parent study: Shanghai Breast Cancer Study. Permanent female residents of Shanghai in 1996-1998 with no previous cancer who were willing to be interviewed.

Exposure Investigated
Exposures investigated
Up to 4 occupations held for at least 3 years and categorized by 3-digit job matrix. Duration of occupation dichotomized as < or > 10 years.
Up to 4 occupations held for at least 3 years and categorized by 3-digit job matrix. Duration of occupation dichotomized as < or > 10 years.
How exposure was measured
Questionnaire, in person Job history
Questionnaire, in person Job history
Exposure assessment comment
Difficult to infer specific chemical exposures from job categories.
Difficult to infer specific chemical exposures from job categories.

Statistical Analysis
Breast cancer outcome investigated
Primary breast cancer
Primary breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
Asian
Confounders considered
Other breast cancer risk factors, such as family history, age at first birth, and hormone replacement therapy use, that were taken into account in the study.
Extensively assessed
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
No
Description of major analysis
Unconditional logistic regression
Unconditional logistic regression
Strength of associations reported
Breast cancer risk was not statistically significantly (p < 0.05) elevated for broad employment categories: medical and public health, teacher, clerical, farmer, rubber & plastic. Elevated risk was seen for some subgroups. Statistically significant adjusted ORs with expected link to environmental pollutants are shown:
Farmer > 10 years OR 2.08 (1.15-3.74) 34 cases, 20 controls
Leather and fur processor OR 3.25 (1.11-9.53) 12 cases, 5 controls
Glass manufacturing workers 2.08 (1.14-3.82) 30 cases, 18 controls; higher risk among premenopausal women OR 2.70 (1.20-6.05); significant dose-response.
Additional elevated odds ratios were statistically unstable.
Average duration of employment of study participants was 24 years.
Breast cancer risk was not statistically significantly (p < 0.05) elevated for broad employment categories: medical and public health, teacher, clerical, farmer, rubber & plastic. Elevated risk was seen for some subgroups. Statistically significant adjusted ORs with expected link to environmental pollutants are shown:
Farmer > 10 years OR 2.08 (1.15-3.74) 34 cases, 20 controls
Leather and fur processor OR 3.25 (1.11-9.53) 12 cases, 5 controls
Glass manufacturing workers 2.08 (1.14-3.82) 30 cases, 18 controls; higher risk among premenopausal women OR 2.70 (1.20-6.05); significant dose-response.
Additional elevated odds ratios were statistically unstable.
Average duration of employment of study participants was 24 years.
Results Comments
Authors suggest possible dioxin and solvent exposure in glass manufacturing. Good control for confounding.
Authors suggest possible dioxin and solvent exposure in glass manufacturing. Good control for confounding.

Author address
Department of Medicine, and Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37232-8300, USA.
Department of Medicine, and Vanderbilt-Ingram Cancer Center, Vanderbilt University, Nashville, Tennessee 37232-8300, USA.