Environment and Breast Cancer: Science Review
About
Body mass index as a prognostic feature in operable breast cancer: the International Breast Cancer Study Group experience. [see comment]
Berclaz, G., Li, S., Price, K. N., Coates, A. S., Castiglione-Gertsch, M., Rudenstam, C. M., Holmberg, S. B., Lindtner, J., Erien, D., Collins, J., Snyder, R., Thurlimann, B., Fey, M. F., Mendiola, C., Werner, I. D., Simoncini, E., Crivellari, D., Gelber, R. D., Goldhirsch, A., International Breast Cancer Study, Group Annals of Oncology. 2004. 15:6, 875-84.
Topic area
Body size
Body size
Study design
Retrospective cohort (prognosis)
Retrospective cohort (prognosis)
Funding agency
NCI
NCI
Study Participants
Number of Cases
5,206 deaths
5,206 deaths
Menopausal Status
Post menopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost menopausal
Number in Cohort
Cohort: 6,370 (breast cancer patients) (3,494 pre/peri) (2,876 post)
Cohort: 6,370 (breast cancer patients) (3,494 pre/peri) (2,876 post)
Country where study was conducted
International (7 study groups from around the worl
International (7 study groups from around the worl
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: women who participated in the International Breast Cancer Study Group (IBCSG) trials from 1978 to 1993
Ex: women who did not have recorded height and weight measurements
Comment about participation selection
Strengths: Large number of breast cancer patients in study; high participation rate; analyzed breast cancer survival by BMI and ER status, menopausal status, nodal status, tumor size and treatment; overall findings are in accordance with earlier studies Limitations: does not specify how anthropometric data were obtained; only BMI was analyzed as an exposure; study was retrospective
Strengths: Large number of breast cancer patients in study; high participation rate; analyzed breast cancer survival by BMI and ER status, menopausal status, nodal status, tumor size and treatment; overall findings are in accordance with earlier studies Limitations: does not specify how anthropometric data were obtained; only BMI was analyzed as an exposure; study was retrospective
How exposure was measured
Not specified
Not specified
Statistical Analysis
Breast cancer outcome investigated
Mortality from breast cancer
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: menopausal status, nodal status, tumor size, vessel invasion, estrogen receptor status, progesterone receptor status, tumor grade and treatment regimens
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: ER status, menopausal status, nodal status, tumor size, and treatment Follow-up: 14 years (median) ER+, ER-
Effect modifiers: ER status, menopausal status, nodal status, tumor size, and treatment Follow-up: 14 years (median) ER+, ER-
Strength of associations reported
Risk of mortality after breast cancer survival increased in women in the obese tertile of BMI, >30 vs <24.9, HR=1.14(1.03-1.27) p trend<0.01
Risk of disease after breast cancer survival increased in women in the obese tertile of BMI, >30 vs <24.9, HR=1.10(1.10-1.20) trend p=0.04
Risk of mortality after breast cancer survival increased in pre/perimenopausal women in the obese tertile of BMI, >30 vs <24.9, HR=1.22(1.05-1.42) trend p=0.01
Risk of disease after breast cancer survival increased in pre/perimenopausal women in the obese tertile of BMI, >30 vs <24.9, HR=1.16(1.02-1.33) trend p=0.03
Risk of mortality after breast cancer survival increased in women in the obese tertile of BMI, >30 vs <24.9, HR=1.14(1.03-1.27) p trend<0.01
Risk of disease after breast cancer survival increased in women in the obese tertile of BMI, >30 vs <24.9, HR=1.10(1.10-1.20) trend p=0.04
Risk of mortality after breast cancer survival increased in pre/perimenopausal women in the obese tertile of BMI, >30 vs <24.9, HR=1.22(1.05-1.42) trend p=0.01
Risk of disease after breast cancer survival increased in pre/perimenopausal women in the obese tertile of BMI, >30 vs <24.9, HR=1.16(1.02-1.33) trend p=0.03
Results Comments
Patients with normal BMI had a significantly longer overall survival and disease free survival than patients with intermediate or obese BMI.
Patients with normal BMI had a significantly longer overall survival and disease free survival than patients with intermediate or obese BMI.
Author address
Department of Obstetrics and Gynecology, Inselspital, Bern, Switzerland. gilles.berclaz@insel.ch
Department of Obstetrics and Gynecology, Inselspital, Bern, Switzerland. gilles.berclaz@insel.ch