Environment and Breast Cancer: Science Review


Evidence From Humans
 
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Body size as a factor in different ages and breast cancer risk in Taiwan
Chie, W. C., Li, C. Y., Huang, C. S., Chang, K. J., Lin, R. S. Anticancer Research. 1998. 18:1B, 565-70.
Topic area
Body size
Study design
Hospital based case-control
Funding agency
Other: Department of Health (China)
Study Participants
Number of Cases
175 (103 pre) (72 post)
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Control: 457 (268 pre) (189 post)
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: women diagnosed with breast cancer at the National Taiwan University Hospital between February 1993 and June 1994 (cases); age matched controls whose medical records were reviewed to ensure eligibility Ex: recurrent breast cancer cases; women with obstetric-gynecological breast, or malignant diseases
Comment about participation selection
Strengths: cases were pathologically confirmed; analyzed breast cancer risk by menopausal status; interviews were conducted by trained interviewers Limitations: hospital based study that does not specify whether or not controls were admitted for weight related illnesses; few cases after stratifying by menopausal status; anthropometric data were self-reported; few remarkable findings; possible misclassification of controls since small breast cancers might have gone undetected
Exposure Investigated
Exposures investigated
Weight before first full term pregnancy (FTP), BMI before first FTP, weight one year before admission, height one year before admission, BMI one year before admission, weight change, BMI change
How exposure was measured
Questionnaire, in person
Exposure assessment comment
Anthropometric data were self-reported
Statistical Analysis
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: education, age at menarche, age at first full term pregnancy, parity, menopausal status, age at menopause, duration of lifetime lactation, OC use, family history of breast cancer
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: Menopausal status
Strength of associations reported
Association between breast cancer risk and women who weighed more before their first full term pregnancy, >60 kg vs. <45 kg, OR=0.5(0.2-1.5)
Association between premenopausal breast cancer risk and women who weighed more one year before admission, >65 kg vs. <50 kg, OR=0.3(0.1-1.0) trend p=0.131
Association between premenopausal breast cancer risk and women who were taller one year before admission, >165 cm vs. <150 cm, OR=0.8(0.2-4.2) trend p=0.939
Association between premenopausal breast cancer risk and women who had a higher BMI one year before admission, >25 vs. <20, OR=0.5(0.2-1.2) trend p=0.163
Association between postmenopausal breast cancer risk and women who weighed more one year before admission, >65 kg vs. <50 kg, OR=1.1(0.3-3.5) trend p=0.916
Association between postmenopausal breast cancer risk and women who were taller one year before admission, >165 cm vs. <150 cm, OR=0.1(0.004-1.3) trend p=0.167
Association between premenopausal breast cancer risk and women who had a higher BMI one year before admission, >25 vs. <20, OR=1.9(0.5-7.3) trend p=0.297
Results Comments
Obesity at younger ages had a protective effect against breast cancer risk, and current obesity had a protective effect against postmenopausal breast cancer