Environment and Breast Cancer: Science Review

Evidence From Humans
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Associations of general and abdominal obesity with multiple health outcomes in older women: the Iowa Women's Health Study
Folsom, A. R., Kushi, L. H., Anderson, K. E., Mink, P. J., Olson, J. E., Hong, C. P., Sellers, T. A., Lazovich, D., Prineas, R. J. Archives of Internal Medicine. 2000. 160:14, 2117-28.
Topic area
Body size
Study design
Prospective cohort
Study Participants
Number of Cases
1299 (postmenopausal)
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number in Cohort
Cohort: 31,702
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: participants of the Iowa Women's Health Study; age 55-69 years; owned a valid Iowa driver's license in 1985; replied to a mailed questionnaire; free of cancer, heart disease and diabetes Ex: premenopausal women; women with a history of breast cancer, heart disease or diabetes; women with missing data on BMI or WHR; women with invalid dietary data
Comment about participation selection
Strengths: large prospective cohort study with a large number of cases; assessed the associations between BMI, waist circumference and WHR with multiple disease end points including breast cancer incidence; lengthy follow up of 11 years (1986-1997) Limitations: anthropometric data were self reported; excluded many potential participants; cohort consisted mainly of elderly white women
Exposure Investigated
Exposures investigated
BMI, waist circumference and WHR
How exposure was measured
Questionnaire, self-administered
Exposure assessment comment
Anthropometric data were self reported
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, education, physical activity, alcohol intake, smoking status, pack-years of cigarette smoking, age of first live birth, estrogen use, vitamin use, energy intake, dietary intake
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
Follow up: 11 years
Strength of associations reported
Association between postmenopausal breast cancer and BMI, >30.21 vs. <22.80, RR=1.6(1.3-1.9) trend p<0.001
Association between postmenopausal breast cancer and WHR, >0.901 vs. <0.762, RR=1.3(1.1-1.5) trend p=0.002
Association between postmenopausal breast cancer and waist circumference, >96.0 cm vs. <74.3 cm, RR=1.7(1.4-2.1) trend p<0.001