Environment and Breast Cancer: Science Review

Evidence From Humans
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Recreational physical activity and breast cancer risk among women under age 45
Gammon, M. D.,, Schoenberg, J. B.,, Britton, J. A.,, Kelsey, J. L.,, Coates, R. J.,, Brogan, D.,, Potischman, N.,, Swanson, C. A.,, Daling, J. R.,, Stanford, J. L.,, Brinton, L. A. American Journal of Epidemiology. 1998. 147:3, 273-280.
Topic area
Physical Activity
Study design
Population based case-control
Study Participants
Number of Cases
1647 (1475 pre) (170 post)
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Controls: 1,501 (1,310 pre) (186 post)
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: women newly diagnosed with invasive or in-situ breast cancer between 5/1/1990 and 12/31/1992 in the US (cases); resident of Atlanta, Seattle or central New Jersey; had a listed telephone number (controls)
Comment about participation selection
Strengths: large population based study of women 45 years of age and younger; fairly good participation rate especially amongst cases; anthropometric measurements taken by interviewer; frequency of vigorous physical activity was assessed for three different time periods; used metabolic equivalent (MET) to quantify the extent of vigorous physical activity performed; participants were from three geographically diverse locations; analyzed effect modification between average activity over the three time periods and age at diagnosis, age at menarche, menopausal status, BMI at 20 years, and BMI in adulthood Limitations: self reported physical activity levels were used for analysis; only assessed recreational physical activity and did not incorporate occupational or daily living activities
Exposures investigated
Sedentary lifestyle
How exposure was measured
Questionnaire, in person
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.
Age, center, age at first birth, age at menarche, parity, lactation, number of abortions, number of miscarriages, menopausal status, marital status, education, family income, race, BMI at age 20, BMI in adulthood, months of oral contraceptive use, use of
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: age at diagnosis, age at menarche, menopausal status, BMI at age 20, BMI in adulthood and Caloric intake during the past year
Strength of associations reported
No association between breast cancer risk and women who had 35.01 to 98.00 METs of recreational physical activity at 20 years of age, OR=1.10(0.88-1.38) compared to women with 1.62-4.73 METs trend p=0.08
No association between breast cancer risk and women who had 35.01 to 98.00 METs of recreational physical activity during the year before interview, OR=1.09(0.87-1.37) compared to women with 1.62-3.35 METs trend p=0.13
Results Comments
The risk of breast cancer among women under the age of 45 years was not associated with self-reported moderate of vigorous activities
Controls participation rate
Greater than 70% (71.2%)