Environment and Breast Cancer: Science Review
About
Baseline recreational physical activity, history of sports participation, and postmenopausal breast carcinoma risk in the Netherlands Cohort Study
Dirx, M. J., Voorrips, L. E., Goldbohm, R. A., van den Brandt, P. A. Cancer. 2001. 92:6, 1638-49.
Topic area
Physical Activity - Body size
Physical Activity - Body size
Study design
Prospective cohort
Prospective cohort
Funding agency
Other: Dutch Cancer Society
Other: Dutch Cancer Society
Study Participants
Number of Cases
1208
1208
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number in Cohort
Cohort: 62,573
Cohort: 62,573
Country where study was conducted
Netherlands
Netherlands
Cohort participation rate
Retention/participation exceeded 70% for exposed a
Retention/participation exceeded 70% for exposed a
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: members of the Netherlands Cohort Study (NLCS); age 55-69 at baseline; completed a self-administered questionnaire
Ex: women with prevalent cancer cases; in situ breast carcinoma cases
Comment about participation selection
Strengths: collected data was key entered twice by research assistants who were blinded with respect to case status; analyzed post breast cancer risk by BMI and physical activity; assessed energy intake; analyzed post breast cancer risk by BMI by energy intake and physical activity; physical activity was measured by several aspects including odd jobs and daily walking; cohort is comparable to the general Dutch population with regard to sports activities; cohort design is prospective in nature Limitations: self-administered questionnaire; few obese cases; loss to follow-up could be a source of selection bias; misclassification and recall bias could play a role in determining early life exposures; misclassification might stem from the methods used to measure physical activity; Anthropometric data self-reported
Strengths: collected data was key entered twice by research assistants who were blinded with respect to case status; analyzed post breast cancer risk by BMI and physical activity; assessed energy intake; analyzed post breast cancer risk by BMI by energy intake and physical activity; physical activity was measured by several aspects including odd jobs and daily walking; cohort is comparable to the general Dutch population with regard to sports activities; cohort design is prospective in nature Limitations: self-administered questionnaire; few obese cases; loss to follow-up could be a source of selection bias; misclassification and recall bias could play a role in determining early life exposures; misclassification might stem from the methods used to measure physical activity; Anthropometric data self-reported
Exposure Investigated
Exposures investigated
Physical inactivity, BMI and weight gain since 20 yrs
Physical inactivity, BMI and weight gain since 20 yrs
How exposure was measured
Questionnaire, self-administered
Questionnaire, self-administered
Exposure assessment comment
Anthropometric and physical activity data self-reported
Anthropometric and physical activity data self-reported
Breast cancer outcome investigated
Primary breast cancer
Primary breast cancer
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
No
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 menarche, age at menopause, benign breast disease, parity, age at first birth, maternal breast carcinoma, breast carcinoma in sister(s), education, height, alcohol use and energy 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.
No
Description of major analysis
Effect modifiers: BMI and weight gain/loss. For analysis of body size, effect modifiers were physical activity and energy intake. Follow up: 7.3 years
Effect modifiers: BMI and weight gain/loss. For analysis of body size, effect modifiers were physical activity and energy intake. Follow up: 7.3 years
Strength of associations reported
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, RR=0.76(0.58-0.99) trend p=0.003
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women with a BMI <25, RR=0.74(0.52-1.08) trend p=0.05
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women with a BMI >30, RR=0.94(0.27-3.32) trend p=0.55
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women who have had a weight gain/loss during life of -35kg to +5kg, RR=0.72(0.38-1.35) trend p=0.05
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, RR=0.76(0.58-0.99) trend p=0.003
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women with a BMI <25, RR=0.74(0.52-1.08) trend p=0.05
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women with a BMI >30, RR=0.94(0.27-3.32) trend p=0.55
Association between postmenopausal breast cancer risk and recreational physical activity, >90 min/day vs. <30 min/day, in women who have had a weight gain/loss during life of -35kg to +5kg, RR=0.72(0.38-1.35) trend p=0.05
Author address
Department of Epidemiology, Maastricht University, Maastricht, The Netherlands. MJM.Dirx@epid.unimaas.nl
Department of Epidemiology, Maastricht University, Maastricht, The Netherlands. MJM.Dirx@epid.unimaas.nl