Environment and Breast Cancer: Science Review

Evidence From Humans
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Manganese superoxide dismutase polymorphism, plasma antioxidants, cigarette smoking, and risk of breast cancer
Tamimi, R. M., Hankinson, S. E., Spiegelman, D., Colditz, G. A., Hunter, D. J. Cancer Epidemiology, Biomarkers and Prevention. 2004. 13:6, 989-96.
Topic area
Diet - Genetic variability
Study design
Nested case-control
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Controls: 1205
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Women in the Nurses' Health Study. Pathologically confirmed, incident breast cancers. Cohort members without BC matched on year of birth, menopausal status, postmenopausal hormone use at blood collection, month of blood return, time of day of blood collection, and fasting status.
Exposures investigated
FFQ, serum cartenoid characterization, allele frequencies of MnSOD, used PCR using a variety of techniques
How exposure was measured
Biological Questionnaire, self-administered
Statistical Analysis
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.
Adequately controlled
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
Logistic regression analysis of MnSOD genotype and antioxidant exposure, including interactions
Strength of associations reported
Ala allele carriers showed no significant risk reduction or increase. Among all women, those homozygous for the Ala allele showed AOR=0.96 (0.74-1.24); No notable differences by menopausal status. No evidence that low consumption of dietary antioxidants (vitamin C or E supplements, multivitamins, total fruits and vegetables, vitamin C dietary intake) increased BC risk, regardless of menopausal status or genotype. There was a reduction in risk for high consumers of total fruits and vegetables among postmenopausal wildtype or heterozygous genotypes, AOR=0.67 (0.53-0.85). Across all forms of carotenoids measured in plasma, no significant interactions were found. For Ala homozygous women in the lowest tertile of alpha-carotene, the estimate suggested an increased risk, AOR=1.41 (0.90-2.25).
Results Comments
Relatively small numbers of premenopausal women in the current study
Author address
Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA. rulla.tamimi@channing.harvard.edu