Environment and Breast Cancer: Science Review

Evidence From Humans
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Physical activity and incidence of postmenopausal breast cancer
Moore, D. B.,, Folsom, A. R.,, Mink, P. J.,, Hong, C. P.,, Anderson, K. E.,, Kushi, L. H. Epidemiology. 2000. 11, 292-296.
Topic area
Physical Activity
Study design
Prospective cohort
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number in Cohort
Cohort: 37,105
Cohort participation rate
Retention/participation exceeded 70% for exposed a
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Postmenopausal women who participated in the Iowa Women's Health Study; age 55-69 years of age; owned an Iowa driver's license; returned completed questionnaires Ex: premenopausal women at baseline; women with prior cancers other than skin cancer; had a total or partial mastectomy
Comment about participation selection
Strengths: one of the few studies to analyze breast cancer risk by physical activity in post women; large cohort study with many cases; prospective study; lengthy follow up of 10 years; study not subject to recall bias since data were obtained before the onset of breast cancer Limitations: self-reported physical activity and anthropometric data; study used a single assessment of physical activity instead of multiple measures; did not measure past or nonleisure physical activity; did not measure the duration or the intensity of of physical activity; obtained data through mailed questionnaires; questionnaires were mailed in the winter which could result in misclassification for women who were more active during the warmer seasons
Exposure Investigated
Exposures investigated
Physical actively
How exposure was measured
Questionnaire, self-administered
Exposure assessment comment
Self-reported physical activity and anthropometric data
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, Confounders: age, age at menopause, age at first live birth, BMI at 18 years, education, family history of breast cancer, estrogen use and WHR
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
Effect modifiers: BMI, parity, HRT use, family history of breast cancer, and energy intake Follow up: 10 years
Results Comments
No significant association between breast cancer risk and leisure physical activity.