Environment and Breast Cancer: Science Review

Fasting glucose is a risk factor for breast cancer: a prospective study
Muti, P., Quattrin, T., Grant, B. J., Krogh, V., Micheli, A., Schunemann, H. J., Ram, M., Freudenheim, J. L., Sieri, S., Trevisan, M., Berrino, F. Cancer Epidemiology, Biomarkers & Prevention. 2002. 11:11, 1361-8.

Topic area
Body size
Body size
Study design
Nested case-control
Nested case-control
Funding agency
Other: Italian Association for Cancer Research
Other: Italian Association for Cancer Research

Study Participants
Number of Cases
133 (69 pre) (64 post) (Invasive only)
133 (69 pre) (64 post) (Invasive only)
Menopausal Status
Post menopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost menopausal
Number of Controls
Controls: 503
Controls: 503
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: women who participated in the ORDET Study between 6/1987 and 6/1992; age 35 to 69 between 6/1987 and 6/1992; resident of Varese province in Northern Italy
Ex: received hormone treatment in the 3 months prior to enrollment; had a bilateral ovariectomy; had a history of cancer; women who had liver disease; women who were pregnant or breast-feeding at time of enrollment; used oral contraceptives; women affected by metabolic diseases influencing the endocrine profile; women with in situ breast cancer
Comment about participation selection
Strengths: several sources of hormone variability were controlled for by both inclusion criteria and highly standardized conditions at blood drawing; laboratory personnel were masked with regard to case-control status; analytical error was controlled for by the analysis of three standardized samples; analyzed breast cancer risk of postmenopausal women with high and low BMI by glucose metabolism and IGF-Is (Insulin-like Growth Factors) Limitations: few cases (133) with short follow-up (5.5 yrs) in parent study; possible selection bias due to a large number of exclusion factors; potentially inaccurate results due to long-term cryopreservation; does not state how data was obtained
Strengths: several sources of hormone variability were controlled for by both inclusion criteria and highly standardized conditions at blood drawing; laboratory personnel were masked with regard to case-control status; analytical error was controlled for by the analysis of three standardized samples; analyzed breast cancer risk of postmenopausal women with high and low BMI by glucose metabolism and IGF-Is (Insulin-like Growth Factors) Limitations: few cases (133) with short follow-up (5.5 yrs) in parent study; possible selection bias due to a large number of exclusion factors; potentially inaccurate results due to long-term cryopreservation; does not state how data was obtained
How exposure was measured
Not specified
Not specified

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 and reproductive variables ( age at menarche, age at menopause, age at first child and number of children)
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: glucose metabolism, IGF-I factors and menopausal status Follow-up: 5.5yrs
Effect modifiers: glucose metabolism, IGF-I factors and menopausal status Follow-up: 5.5yrs
Strength of associations reported
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of free IGF-Is, RR=5.5(1.61-18.71) p=0.003
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of insulin, RR=2.16(0.62-7.52) p=0.06
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of IGFBP-I, RR=0.59 (0.18-1.88) p=0.03
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of IGFBP-2, RR=0.58 (0.19-1.80) p=0.02
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of free IGF-Is, RR=5.5(1.61-18.71) p=0.003
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of insulin, RR=2.16(0.62-7.52) p=0.06
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of IGFBP-I, RR=0.59 (0.18-1.88) p=0.03
Increased breast cancer risk among postmenopausal women with high BMIs, >26, who had high levels of IGFBP-2, RR=0.58 (0.19-1.80) p=0.02
Results Comments
Modest association of insulin levels with breast cancer risk among overweight postmenopausal women Association of insulin levels with breast cancer risk among premenopausal women not as prominent
Modest association of insulin levels with breast cancer risk among overweight postmenopausal women Association of insulin levels with breast cancer risk among premenopausal women not as prominent

Author address
Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo 14214, USA.
Department of Social and Preventive Medicine, University at Buffalo, State University of New York, Buffalo 14214, USA.
Controls participation rate
Greater than 70%
Greater than 70%