Environment and Breast Cancer: Science Review


Evidence From Humans
 
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Waist-to-hip ratio and breast cancer mortality
Borugian, M. J., Sheps, S. B., Kim-Sing, C., Olivotto, I. A., Van Patten, C., Dunn, B. P., Coldman, A. J., Potter, J. D., Gallagher, R. P., Hislop, T. G. American Journal of Epidemiology. 2003. 158:10, 963-8.
Topic area
Body size
Study design
Prospective cohort
Funding agency
Other: Canadian Breast Cancer Research Foundation
Study Participants
Number of Cases
110 deaths from breast cancer (invasive and in situ)
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number in Cohort
Cohort: 586
Cohort participation rate
Retention/participation exceeded 70% for exposed a
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: age 19-75 years at baseline; visited the Vancouver Cancer Centre of the British Columbia Cancer Agency between 7/1991 and 12/1992; diagnosed with invasive or in situ breast cancer Ex: women who have had a previous tumor; patients who have undergone any hormone, ablation or chemotherapy treatment for breast cancer prior to referral; did not speak English; over the age of 75; women with stage IV breast cancer; woment with missing data
Comment about participation selection
Strengths: women completed the questionnaire before adjuvant therapy; tumor size and nodal status were derived from pathology reports for >90% of participants; analyzed breast cancer mortality according to WHR by menopausal status; analyzed breast cancer mortality according to WHR by estrogen receptor status; prospective study; 10 year follow-up; high participation rate; used detailed actively updated patient records Limitations: self-administered questionnaire; anthropometric data self-reported; lack of accuracy and reliability of self measurement of WHR could lead to misclassification; cohort largely made up of urban Caucasian women; potential misclassification of menopausal status since age 50 was used as the cut-off for 8% of the cohort members who did not have menopausal data recorded; did not consider HRT use and progesterone receptor status in study
Exposure Investigated
How exposure was measured
Questionnaire, self-administered
Exposure assessment comment
Anthropometric data self-reported
Breast cancer outcome investigated
Mortality from 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, BMI, family history of breast cancer, estrogen receptor status, stage at diagnosis, and systemic treatment
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+, ER- Effect modifiers: menopausal status, estrogen receptor status Follow-up: 10 years
Strength of associations reported
Association between breast cancer mortality and WHR in premenopausal women, >0.848 vs. <0.756, RR=1.2(0.4-3.4)
WHR was directly related to breast cancer mortality in postmenopausal women, >0.848 vs. <0.756, RR=3.3(1.1-10.4)
Association of elevated WHR with premenopausal breast cancer mortality in women with ER-positive tumors, RR=1.3(0.6-2.5)
Association of elevated WHR with postmenopausal breast cancer mortality in women with ER-positive tumors, RR=1.6(1.0-2.4)
Author address
Cancer Control Research Program, British Columbia Cancer Agency, Vancouver, British Columbia, Canada. mborugia@bccancer.bc.ca