Environment and Breast Cancer: Science Review

Case-control study of anthropometric measures and breast cancer risk
Friedenreich, C. M., Courneya, K. S., Bryant, H. E. International Journal of Cancer. 2002. 99:3, 445-52.

Topic area
Body size
Body size
Study design
Population based case-control
Population based case-control
Funding agency
Other:Canadian Breast Cancer Research Initiative
Other:Canadian Breast Cancer Research Initiative

Study Participants
Number of Cases
1233 (in situ and invasive) (462 premenopausal) (771 postmenopausal)
1233 (in situ and invasive) (462 premenopausal) (771 postmenopausal)
Menopausal Status
Post menopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost menopausal
Number of Controls
Controls: 1237 (475 premenopausal) (762 postmenopausal)
Controls: 1237 (475 premenopausal) (762 postmenopausal)
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Resident of Alberta, 80 years or younger at baseline, English speaking, no previous cancer diagnosis and diagnosed with in situ or invasive breast cancer between 1995-1997 (cases)
Ex: missing or questionable data for several risk factors
Comment about participation selection
Strengths: large population based sample, made a complete assessment of confounding and effect modification, anthropometric data recorded by trained interviewers at interview and obtained data on weight changes across lifetime Limitations: Low response rate among controls, random error attributed to difficulty remembering weight by decade and social desirability bias in recollecting anthropometric data, smaller number of premenopausal women
Strengths: large population based sample, made a complete assessment of confounding and effect modification, anthropometric data recorded by trained interviewers at interview and obtained data on weight changes across lifetime Limitations: Low response rate among controls, random error attributed to difficulty remembering weight by decade and social desirability bias in recollecting anthropometric data, smaller number of premenopausal women

Exposure Investigated
Exposures investigated
Height, weight, BMI, waist circumference, hip circumference, W/H ratio, weight at 20 yrs, weight gain since 20 yrs, sum of weight changes between decades, difference between maximum and minimum lifetime weights, and reference weight minus min weight since
Height, weight, BMI, waist circumference, hip circumference, W/H ratio, weight at 20 yrs, weight gain since 20 yrs, sum of weight changes between decades, difference between maximum and minimum lifetime weights, and reference weight minus min weight since
How exposure was measured
Questionnaire, in person
Questionnaire, in person

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, caloric intake, lifetime physical activity, education, HRT use, benign breast cancer, family history of breast cancer, alcohol consumption, smoking habits
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 modification: HRT use and menopausal status Interactions: HRT use
Effect modification: HRT use and menopausal status Interactions: HRT use
Strength of associations reported
Unrelated to risk in either pre or postmenopausal women: Height, weight, BMI, waist circumference, hip circumference, weight at age 20
Waist/Hip ratio predictive of risk only in postmenopausal women > 0.81 vs. <0.72, OR= 1.43 (1.07-1.93) trend p = 0.0006 result restricted to never-users of HRT
Weigh gain since age 20 predictive of risk > 20 kg vs. <7.72 OR=1.35 (1.01-1.81) trend p=0.05
Unrelated to risk in either pre or postmenopausal women: Height, weight, BMI, waist circumference, hip circumference, weight at age 20
Waist/Hip ratio predictive of risk only in postmenopausal women > 0.81 vs. <0.72, OR= 1.43 (1.07-1.93) trend p = 0.0006 result restricted to never-users of HRT
Weigh gain since age 20 predictive of risk > 20 kg vs. <7.72 OR=1.35 (1.01-1.81) trend p=0.05
Results Comments
Waist/Hip ration results were restricted to never-users of HRT.
Waist/Hip ration results were restricted to never-users of HRT.

Author address
Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Canada. chrisf@cancerboard.ab.ca
Division of Epidemiology, Prevention and Screening, Alberta Cancer Board, Calgary, Canada. chrisf@cancerboard.ab.ca
Controls participation rate
Less than 70% (56%)
Less than 70% (56%)