Environment and Breast Cancer: Science Review

Evidence From Humans
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The relation of breast size to breast cancer risk in postmenopausal women (United States)
Egan, K. M., Newcomb, P. A., Titus-Ernstoff, L., Trentham-Dietz, A., Baron, J. A., Willett, W. C., Stampfer, M. J., Trichopoulos, D. Cancer Causes & Control. 1999. 10:2, 115-8.
Topic area
Body size
Study design
Population based case-control
Funding agency
Not reported
Study Participants
Number of Cases
Cases: 2,015 (invasive only)
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number of Controls
Control: 2,556
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Participants of the Collaborative Breast Cancer Study (CBCS): age 50-79 yrs at baseline, new diagnosis of invasive breast cancer between 1992 and 1995 (cases) Ex: Women without drivers licenses (controls age 64 and younger); without Medicare benefits (controls age 65 and older)
Comment about participation selection
Strengths: Large case-control study, 161 cases and 166 controls were re-interviewed 3.5 (median) months later to assess reliability of data (concordance between responses was high) Limitations: Bra cup size and back circumference, anthropometric data self-reported and slightly high level of non-response (17% of cases and 22% of controls)
Exposure Investigated
Exposures investigated
Bra cup size and back circumference
How exposure was measured
Questionnaire, by telephone
Exposure assessment comment
Anthropometric data 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 at menarche, parity and race adjusted for age, state, current BMI and height, first degree family history of breast cancer and benign breast disease
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 modification: back circumference
Strength of associations reported
Association between breast cancer risk and bra cup size in women whose back circumference was less than 34 inches, >C cup vs. < A cup, RR=1.76(1.04-3.01) trend p=0.005
Association between breast cancer risk and bra cup size in women whose back circumference was more than 34 inches, >C cup vs. < A cup, RR=0.76(0.49-1.18) trend p=0.33
Author address
Department of Epidemiology, Harvard School of Public Health, Boston, MA 02115, USA.
Controls participation rate
Greater than 70% (78%)