Environment and Breast Cancer: Science Review

A population-based case-control study of the Arg399Gln polymorphism in DNA repair gene XRCC1 and risk of breast cancer
Shu, X. O., Cai, Q., Gao, Y. T., Wen, W., Jin, F., Zheng, W. Cancer Epidemiology, Biomarkers and Prevention. 2003. 12:12, 1462-7.

Topic area
Body size - Genetic variability
Body size - Genetic variability
Study design
Population based case-control study
Population based case-control study
Funding agency
USPHS, NCI
USPHS, NCI

Study Participants
Number of Cases
1088
1088
Menopausal Status
Post meopausal
The menopausal status of women included in this study is listed here.
Pre menopausalPost meopausal
Number of Controls
1182
1182
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Participants of the Shanghai Breast Cancer Study. Rapid case ascertainment system with population-based Shanghai Tumor Registry, pathologist confirmed diagnosis. Controls selected by Shanghai Resident Registry and frequency matched by age in 5-year intervals.
Exposures investigated
BMI, XRCC1 allele frequencies, used PCR-RFLP
BMI, XRCC1 allele frequencies, used PCR-RFLP
How exposure was measured
Biological Questionnaire, in-person
Biological Questionnaire, in-person
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
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Yes
Description of major analysis
Logistic regression analysis of XRCC1 genotype and breast cancer, including effect modification by BMI
Logistic regression analysis of XRCC1 genotype and breast cancer, including effect modification by BMI
Strength of associations reported
In the full sample, heterozygotes (Arg/Gln) showed an adjusted OR=0.90 (0.76-1.08) and homozygotes (Gln/Gln) showed an adjusted OR of 1.20 (0.85-1.69) compared to wild type homozygotes (Arg/Arg)
For BMI <25, age-adjusted OR=0.92 (CI: 0.74-1.13) for Arg/Gln and 1.36 (CI: 0.93-2.01) in Gln/Gln
For BMI >=25, age-adjusted OR=0.88 (CI: 0.63-1.22) in Arg/Gln and 0.92 (CI: 0.44-1.91) in Gln/Gln
No statistically significant associations when BMI stratified analyses were computed for only postmenopausal women
In the full sample, heterozygotes (Arg/Gln) showed an adjusted OR=0.90 (0.76-1.08) and homozygotes (Gln/Gln) showed an adjusted OR of 1.20 (0.85-1.69) compared to wild type homozygotes (Arg/Arg)
For BMI <25, age-adjusted OR=0.92 (CI: 0.74-1.13) for Arg/Gln and 1.36 (CI: 0.93-2.01) in Gln/Gln
For BMI >=25, age-adjusted OR=0.88 (CI: 0.63-1.22) in Arg/Gln and 0.92 (CI: 0.44-1.91) in Gln/Gln
No statistically significant associations when BMI stratified analyses were computed for only postmenopausal women

Controls participation rate
Greater than 70%
Greater than 70%