Environment and Breast Cancer: Science Review

Evidence From Humans
Print this page
Repeated measurements of organochlorine exposure and breast cancer risk (Denmark)
Hoyer, A. P., Jorgensen, T., Grandjean, P., Hartvig, H. B. Cancer Causes and Control. 2000. 11:2, 177-84.
Topic area
Environmental pollutant - Pesticides, organochlorine, PCB, beta HCH, Dieldri
Study design
Nested case-control
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Number of Controls
Controls: 274
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
In: Participants of the Copenhagen City Heart Study. Controls were matched to cases based on age and vital statistics at the time of the case diagnosis.
Exposures investigated
The average of two lipid-adjusted serum concentrations of PCBs, DDE, DDT, HCH, and Dieldrin, taken at a 5-year interval.
Statistical Analysis
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
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.
Parity, body weight, HRT use, change in body weight between examinations.
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked “Yes.” “No”, if not.
Description of major analysis
Conditional logistic regression was used to calculate the ORs.
Strength of associations reported
All of the ORs which had previously calculated based on only one exposure measurement were strengthened when the average of the repeated measurements were used. Previously, no statistically significantly elevated ORs were seen for any compound except Dieldrin (which was not analyzed in the repeated measure analysis).
For the repeated measure analysis, significantly elevated ORs were seen for PCB congener 138, and DDT.
Results Comments
These results suggest the possibility that the single serum concentrations which are used as the exposure measure in most studies may not be adequate.
Author address
Copenhagen Center for Prospective Populations Studies, Denmark. APH@post8.tele.dk