Environment and Breast Cancer: Science Review

Evidence From Humans
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Accumulation of environmental estrogens in adipose tissue of breast cancer patients
Ociepa-Zawal, M., Rubis, B., Wawrzynczak, D., Wachowiak, R., Trzeciak, W. H. J Environ Sci Health A Tox Hazard Subst Environ En. 2010. 45:3, 305-12.
Topic area
Environmental pollutant - Organochlorine Pesticides
Study design
Hospital based case-control
Funding agency
Not reported
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analysis based on menopausal status
Number of Controls
Controls: 23
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Cases were women with primary breast cancer diagnosed at the Poznan University of Medical Sciences between the ages of 36 and 87. Hospital-controls were aged 31 to 74 years, without "symptoms of cancer" and treated at the Department of Oncological Gynecology at the same facility.
Comment about participation selection
The time-frame for recruitment of both cases and controls was not discussed. This information is needed to put the exposure time in and frequency of incident cases in context, and to assess whether cases and controls were comparable. In general, the lack of detail about control selection limits interpretation of the results. No matching criteria were used and on the whole, cases were older than controls.
Exposure Investigated
Exposures investigated
Adipose tissue concentrations of various pesticides in µg/kg fat, including HCB, HCH, DDE, DDD, DDT, aldrin, dieldrin, endrin, and Heptachlor. Cases had breast adipose tissue excised, while controls gave samples from abdominal adipose tissue.
Exposure assessment comment
As in the USA, Poland used DDT until it was banned in the 1970s. It was not stated whether samples were taken before treatment which could affect weight loss-related adipose tissue releases of estrogens or previously stored chemicals. The adipose tissue concentration of selected pesticides may or may not correctly rank the exposures relevant to disease.
Breast cancer outcome investigated
Primary incident breast cancer
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.
Self-reported environmental estrogen exposure, location of residence, smoking status, employment status, BMI, age at diagnosis/interview, family history, drug use, and clinical tumor characteristics (TNM stage, grade, and hormone receptor status).
Genetic characterization included
If the study analyzed relationships between environmental factors and inherited genetic variations, this field will be marked Yes. No, if not.
Strength of associations reported
Median levels, mg/kg fat, cases vs. controls:
HCB: 0.014 vs. 0.009
α-HCH: 0.007 vs. 0.024
γ-HCH: 0.024 vs. 0.008
β-HCH: 0.04 vs. 0.018
All HCH: 0.046 vs. 0.025
DDE: 0.642 vs. 0.593
DDD: 0.019 vs. 0.013
DDT: 0.138 vs. 0.091
All DDT: 0.865 vs. 0.773
Heptachlor: 0.007 vs. 0.004
Heptachlor epoxide: 0.012 vs. 0

When analyses were stratified by hormone receptor status, ER+ patients had significantly higher median levels of β-HCH than controls (p=0.049).
Results Comments
The selected compounds were detected in all samples, with the exception of aldrin, dieldrin, and endrin which were not detected in any samples and heptachlor/heptachlor epoxide which was only found in a few participants. The authors report that concentrations, overall, are lower compared to earlier studies made by other European countries.
Author address
Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, Poznan, Poland.
Reviewers Comments
Given the limited information about control selection, it is not clear whether the comparison group is appropriate. Comparisons were not adjusted for age, despite the fact that cases were significantly older than controls. Further, concentrations in abdominal tissue (controls) may not be an appropriate comparison to concentrations in the target tissue (cases).