Environment and Breast Cancer: Science Review

Height, weight weight change, and postmenopausal breast cancer risk: The Netherlands Cohort Study
van den Brandt, P. A., Dirx, M. J., Ronckers, C. M., van den Hoogen, P., Goldbohm, R. A. Cancer Causes & Control. 1997. 8:1, 39-47.

Topic area
Body size
Body size
Study design
Other: case-cohort
Other: case-cohort
Funding agency
Other: Dutch Cancer Society
Other: Dutch Cancer Society

Study Participants
Number of Cases
626 (invasive only)
626 (invasive only)
Menopausal Status
The menopausal status of women included in this study is listed here.
Post menopausal
Number in Cohort
Cohort: 62,573, (1652 subcohort members)
Cohort: 62,573, (1652 subcohort members)
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: participants of the Netherlands Cohort Study (NLCS); Dutch women age 55-69 years at baseline, and diagnosed with invasive breast cancer between 9/86 and 12/90 (cases)
Ex: women who reported prevalent cancers other than skin cancer, cases without microscopic confirmation of diagnosis, women with incomplete anthropometric data and women with carcinoma in situ
Comment about participation selection
Strengths: completeness of cancer follow up was 96%, found that the mean values of self-reported height and weight at baseline of women in NLCS were comparable to a representative sample of Dutch women in 1985-88, high completeness of cancer follow-up and PY (person years) follow-up decreased chances of selection bias, and the interval between weight assessment and diagnosis was longer than in most case-control studies Limitations: short follow up period (4.3 years) and anthropometric data self-reported
Strengths: completeness of cancer follow up was 96%, found that the mean values of self-reported height and weight at baseline of women in NLCS were comparable to a representative sample of Dutch women in 1985-88, high completeness of cancer follow-up and PY (person years) follow-up decreased chances of selection bias, and the interval between weight assessment and diagnosis was longer than in most case-control studies Limitations: short follow up period (4.3 years) and anthropometric data self-reported

Exposure Investigated
Exposures investigated
Height, weight, BMI, weight at 20 years, BMI at 20 years, weight change and BMI change
Height, weight, BMI, weight at 20 years, BMI at 20 years, weight change and BMI change
How exposure was measured
Questionnaire, self-administered
Questionnaire, self-administered
Exposure assessment comment
Anthropometric data self-reported
Anthropometric data self-reported

Statistical Analysis
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, history of benign breast disease, family history of breast cancer, age at menarche, age at menopause, parity, age at first birth and 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.
No
Description of major analysis
Effect modifiers: age Follow-up: 4.3 years
Effect modifiers: age Follow-up: 4.3 years
Strength of associations reported
Risk increased with height (RR=1.35 per 10 cm increment, 95% CI=1.15-1.59) trend p<0.001
Association between breast cancer risk and weight, trend 10 kg increment, RR=1.09(0.98-1.21) trend p=0.23
Association between breast cancer risk and BMI, trend 8 kg/m^2 increment, RR=1.11(0.88-1.39) trend p=0.46
Weak inverse association for age 20 weight (RR for 10kg increment=0.94, 95% CI=0.82-1.09) and BMI (8 kg/m^2 increment) at age 20, RR=0.79(0.58-1.08) trend p=0.03
Risk increased with height (RR=1.35 per 10 cm increment, 95% CI=1.15-1.59) trend p<0.001
Association between breast cancer risk and weight, trend 10 kg increment, RR=1.09(0.98-1.21) trend p=0.23
Association between breast cancer risk and BMI, trend 8 kg/m^2 increment, RR=1.11(0.88-1.39) trend p=0.46
Weak inverse association for age 20 weight (RR for 10kg increment=0.94, 95% CI=0.82-1.09) and BMI (8 kg/m^2 increment) at age 20, RR=0.79(0.58-1.08) trend p=0.03
Results Comments
No consistent trend in risk for adult weight gain
No consistent trend in risk for adult weight gain

Author address
Department of Epidemiology, Maastricht University, The Netherlands.
Department of Epidemiology, Maastricht University, The Netherlands.