Environment and Breast Cancer: Science Review

Plasma carotenoids, retinol, and tocopherols and risk of breast cancer
Tamimi, R. M., Hankinson, S. E., Campos, H., Spiegelman, D., Zhang, S., Colditz, G. A., Willett, W. C., Hunter, D. J. Am J Epidemiol. 2005. 161:2, 153-60.

Topic area
Diet
Diet
Study design
Nested case-control
Nested case-control
Funding agency
NCI
NCI

Study Participants
Number of Cases
969
969
Menopausal Status
Pre menopausal
The menopausal status of women included in this study is listed here.
Post menopausalPre menopausal
Number in Cohort
Controls: 969, cohort: 32,826
Controls: 969, cohort: 32,826
Cohort participation rate
Not reported
Not reported
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Women who returned the initial questionnaire of the Nurses' Health Study in 1976 (US registered nurses between the ages of 30 and 55 years in 1976)
Eligible cases: women with pathologically confirmed, incident invasive and in situ breast cancer from the subcohort of women who returned a blood sample and were diagnosed by June 1, 1998. Cases were excluded if they reported any other prior cancer diagnosis except for nonmelanoma skin cancer.
Controls: randomly selected from the subcohort of women who returned a blood sample and never reported a diagnosis of cancer except for non-melanoma skin cancer.
Comment about participation selection
Largest cohort study for biological markers and risk of breast cancer
Largest cohort study for biological markers and risk of breast cancer

Exposure Investigated
Exposures investigated
Alpha-carotene, beta-carotene, alpha-tocopherol
Alpha-carotene, beta-carotene, alpha-tocopherol
How exposure was measured
Biological
Biological
Exposure assessment comment
Lack of information about the stability of the biomarkers (i.e. latency between blood being drawn and stored in nitrogen freezers).
Lack of information about the stability of the biomarkers (i.e. latency between blood being drawn and stored in nitrogen freezers).

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.
No
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.
Not considered: Race
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
Adjusted OR with 95% CI, highest versus lowest quintile of plasma nutrients, stratification by ER, lymphatic node status, and differentiation of tumor cells. Follow-up 9-10 years
Adjusted OR with 95% CI, highest versus lowest quintile of plasma nutrients, stratification by ER, lymphatic node status, and differentiation of tumor cells. Follow-up 9-10 years
Strength of associations reported
Beta-carotene: 0.73 (0.53-1.02); alpha-tocopherol: 0.79 (0.57-1.08)
Beta-carotene: 0.73 (0.53-1.02); alpha-tocopherol: 0.79 (0.57-1.08)
Results Comments
The inverse association between beta-carotene and risk of breast cancer was attenuated upon adjustment for alpha-carotene.
The inverse association between beta-carotene and risk of breast cancer was attenuated upon adjustment for alpha-carotene.

Author address
Channing Laboratory, Department of Medicine, 181 Longwood Avenue, Boston, MA 02115, USA. rulla.tamimi@channing.harvard.edu
Channing Laboratory, Department of Medicine, 181 Longwood Avenue, Boston, MA 02115, USA. rulla.tamimi@channing.harvard.edu