Environment and Breast Cancer: Science Review

Evidence From Humans
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Serum polychlorinated biphenyls, cytochrome P-450 1A1 polymorphisms, and risk of breast cancer in Connecticut women
Zhang, Y., Wise, J. P., Holford, T. R., Xie, H., Boyle, P., Zahm, S. H., Rusiecki, J., Zou, K., Zhang, B., Zhu, Y., Owens, P. H., Zheng, T. American Journal of Epidemiology. 2004. 160:12, 1177-83.
Topic area
Environmental pollutant - Genetic variability, organochlorine, PCB,
Study design
Other: Case-control study with controls from population and hospital settings
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post meopausal
Number of Controls
Controls: 406
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Cases and controls were women undergoing breast surgery at Yale-New Haven hospital in the Yale-New Haven Breast Cancer study Cases were histologically confirmed incident cases identified in two counties via Yale-New Haven Hospital records. Controls were frequency matched 1:1 with cases in 5-year age intervals, from two sources: Yale-New Haven Hospital Records in one county and random digit dialing in second county. Controls were women without breast cancer or atypical hyperplasia, and included women with benign breast diseases, and women with normal tissue.
Exposures investigated
Lipid-adjusted serum total PCBs; CYP1A1 variants m1, m2, and m4; used PCR and RFLP
How exposure was measured
Biological Questionnaire, in person
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
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.
Age, BMI, duration of breastfeeding, family history of breast cancer, menopausal status, annual household income, and study site.
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Unconditional logistic regression was used to calculate the ORs. Logistic regression analysis of CYP1A1 frequencies and cancer risk, including effect modification by PCB level
Strength of associations reported
No significant relation between PCB level and BC risk among pre or postmenopausal women
Only m2 showed a significant relationship to BC risk, with AOR=2.4 (1.1-5.0) for postmenopausal women; No association in premenopausal women
The breast cancer OR for women with high PCB levels (greater than median of controls) and the CYP1A1-m2 polymorphism was 4.3 (95% CI: 1.6-12.0) among postmenopausal women, and 2.2 (0.4-1.2) among premenopausal women (compared to women with the wild-type polymorphism and low PCB levels).
m1 showed AOR=1.8 (1.0-3.2) among postmenopausal women with variant genotype and high PCB exposure
Author address
Department of Epidemiology and Public Health, School of Medicine, Yale University, New Haven, CT 06510, USA.