Environment and Breast Cancer: Science Review

Evidence From Humans
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Case-control study of physical activity and breast cancer risk among premenopausal women in Germany
Steindorf, K.,, Schmidt, M.,, Kropp, S.,, Chang-Claude, J. American Journal of Epidemiology. 2003. 157, 121-130.
Topic area
Physical Activity
Study design
Population based case-control
Funding agency
Other: German Cancer Aid
Study Participants
Number of Cases
360 (in situ and invasive)
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Number of Controls
Controls: 886
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: German speaking residents of Rhein-Neckar-Odenwald and Freiburg (southern Germany) diagnosed with in situ or invasive breast cancer between 1992 and 1995 (cases); 51 years of age or younger; matched to cases by age and study region (controls) Ex: postmenopausal women
Comment about participation selection
Strengths: analyzed physical activity by occupation, sports, household tasks, walking, and cycling; analyzed the frequency, duration and intensity of physical activity during adolescence and young adulthood; interviewers were blinded to the case-control status of the participant; intensity of physical activity was measured in METs; one of the first case-control studies that investigated physical activity and breast cancer risk in Germany Limitations: physical activity and anthropometric data were self-reported; possible selection bias because from participants being lost when women were recontacted by telephone to obtain physical activity data; few cases; low participation rate
Exposure Investigated
Exposures investigated
Physical inactivity
How exposure was measured
Questionnaire, self-administered
Exposure assessment comment
Physical activity and anthropometric data were self-reported
Early life exposures considered
Physical activity from age 12-19 years
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: family history of breast cancer, number of full term pregnancies, height, change in BMI between 20 and 30 years, months of breastfeeding, alcohol consumption
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Results Comments
No association between breast cancer risk and physical activity between ages 12 and 19, 134.1-695.9 METs vs. 13.0-55.7 METs, OR=0.73(0.50-1.07) trend p=0.44 No association between breast cancer risk and physical activity between ages 20 and 30, 160.5-728.8 METs vs. 6.4-69.0 METs, OR=0.96(0.67-1.39) trend p=0.32 No association between breast cancer risk and occupational physical activity, 35.1-170.5 METs vs. 0 METs, OR=0.83(0.59-1.18) trend p=0.56
Controls participation rate
Less than 70% (48.4%)