Environment and Breast Cancer: Science Review
About
Population-based case-control study of soyfood intake and breast cancer risk in Shanghai
Dai, Q., Shu, X. O., Jin, F., Potter, J. D., Kushi, L. H., Teas, J., Gao, Y. T., Zheng, W. British Journal of Cancer. 2001. 85:3, 372-8.
Topic area
Body size
Body size
Study design
Population based case-control
Population based case-control
Funding agency
NCI
NCI
Study Participants
Number of Cases
1459
1459
Menopausal Status
Postmenopausal
The menopausal status of women included in this study is listed here.
PremenopausalPostmenopausal
Number of Controls
Controls: 1556
Controls: 1556
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: participants of the Shanghai Breast Cancer Study; age 25 to 64 at diagnosis; diagnosed with breast cancer from August 1996 to March 1998; permanent resident of urban Shanghai
Ex: prior history of cancer
Comment about participation selection
Strengths: in-person interviews; cancers confirmed and reviewed by 2 senior pathologists; estrogen and progesterone status noted; anthropometric data measured by trained staff; used food frequency questionnaire to obtain usual dietary intake of soy products; large pop-based case control study; nearly half of the cases were interviewed before they received treatment; analyzed breast cancer risk by BMI and soy protein intake; first study designed specifically to investigate the association of soyfood intake with breast cancer risk Limitations: cases were slightly older than controls; possible errors in assessing soyfood intake could bias results; diets of cases may have changed after cancer diagnosis; analyzed few exposures
Strengths: in-person interviews; cancers confirmed and reviewed by 2 senior pathologists; estrogen and progesterone status noted; anthropometric data measured by trained staff; used food frequency questionnaire to obtain usual dietary intake of soy products; large pop-based case control study; nearly half of the cases were interviewed before they received treatment; analyzed breast cancer risk by BMI and soy protein intake; first study designed specifically to investigate the association of soyfood intake with breast cancer risk Limitations: cases were slightly older than controls; possible errors in assessing soyfood intake could bias results; diets of cases may have changed after cancer diagnosis; analyzed few exposures
Exposures investigated
BMI and W/H ratio
BMI and W/H ratio
How exposure was measured
Questionnaire, in person Anthropometric measurement, researcher-administered
Questionnaire, in person Anthropometric measurement, researcher-administered
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.
Chinese
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, education, first degree family history of bc, history of breast fibroadenoma, W/H ratio, age at menarche, physical activity, birth of > 1 child, age at first live birth, menopausal status, age at menopause, 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
ER+-/PR+- status Effect modifiers: soy protein intake
ER+-/PR+- status Effect modifiers: soy protein intake
Strength of associations reported
Association between breast cancer risk and women with a BMI >25 in the highest soy protein intake group, OR=0.30(0.10-0.94) trend p=0.15
Association between breast cancer risk and women with a BMI <25 in the highest soy protein intake group, OR=0.76(0.46-1.25) trend p=0.49
Association between breast cancer risk and women with a WHR <0.84 in the highest soy protein intake group, OR=0.72(0.43-1.19) trend p=0.29
Association between breast cancer risk and women with a WHR >0.84 in the highest soy protein intake group, OR=0.61(0.25-1.51) trend p=0.20
Association between breast cancer risk and women with a BMI >25 in the highest soy protein intake group, OR=0.30(0.10-0.94) trend p=0.15
Association between breast cancer risk and women with a BMI <25 in the highest soy protein intake group, OR=0.76(0.46-1.25) trend p=0.49
Association between breast cancer risk and women with a WHR <0.84 in the highest soy protein intake group, OR=0.72(0.43-1.19) trend p=0.29
Association between breast cancer risk and women with a WHR >0.84 in the highest soy protein intake group, OR=0.61(0.25-1.51) trend p=0.20
Results Comments
Potential protective effect of soy protein intake may be more pronounced in women with a greater BMI and WHR.
Potential protective effect of soy protein intake may be more pronounced in women with a greater BMI and WHR.
Author address
Vanderbilt-Ingram Cancer Center and Department of Medicine, Vanderbilt University, Nashville, TN, 37232-8300, USA.
Vanderbilt-Ingram Cancer Center and Department of Medicine, Vanderbilt University, Nashville, TN, 37232-8300, USA.
Controls participation rate
Greater than 70%
Greater than 70%