Environment and Breast Cancer: Science Review

Evidence From Humans
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DDT Exposure in Utero and Breast Cancer
Cohn, B. A., La Merrill, M., Krigbaum, N.Y., Yeh, G., Park, J.-S., Zimmermann, L., Cirillo, P. M. J Clin Endocrinol Metab. 2015. .
Topic area
Environmental pollutant - DDT DDE Organochlorine pesticides
Study design
Nested case-control
Funding agency
CBCRP NIEHS NIH Department of Health and Human Ser
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
No analysis based on menopausal status (all cases were < 52 years old, we can assume the majority were premenopausal)
Number of Controls
Controls: 315
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
Participants were selected from the 9,300 daughters of women who enrolled in the Child Health and Development Studies (CHDS) cohort and members of the Kaiser Permanente Health Plan, recruited when they sought obstetric care between 1959-1967. All participants were required to have a maternal perinatal blood sample taken during the enrollment period and information on maternal lipids, age, race, early pregnancy weight, height, history of breast cancer, and breast feeding history. Cases were identified via surveillance and self-report through March 2013 and included in the study if they had been diagnosed by the age of 52. 315 controls from the CHDS cohort were matched to cases on birth year and trimester of maternal blood draw and free of breast cancer at the age of diagnosis of the case.
Exposure Investigated
Exposures investigated
Serum p,p'-DDE, o,p'-DDT and p,p'-DDT measured in samples collected from mothers within 1-3 days of delivery (>75%) or during pregnancy as proxy for in utero exposure.
Exposure assessment comment
When possible, early postpartum serum samples were selected for analysis, followed by third-, second-, and first-trimester samples. The overlap between the timing of sample collection and peak DDT use provides a unique opportunity to study in utero exposure. Given rapid metabolism of o,p'-DDT, may serve as a marker of recent exposure.
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.
Mother's age, race, early pregnancy weight, height, history of breast cancer, serum lipids, and whether CHDS daughter was breast fed.
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
Adjusting for other compounds (95% CI not reported):
p,p'-DDT, 4th quartile vs. 1st quartile: aOR 1.4
p,p'-DDE, 4th quartile vs. 1st quartile: aOR 0.6
o,p'-DDT, 4th quartile vs. 1st quartile: aOR 3.5 (p=0.019)

Adjusting for p,p'-DDE:
o,p'-DDT, 4th quartile vs. 1st quartile: aOR 3.7 (95% CI 1.5-9.0)

For cases with advanced stage diagnosis, adjusting for p,p'-DDE:
o,p'-DDT, 4th quartile vs. 1st quartile: aOR 4.6 (95% CI 1.3-16.5)

For cases with HER2-positive tumor, adjusting for p,p'-DDE:
o,p'-DDT, 4th quartile vs. 1st quartile: aOR 4.6 (95% CI 1.1-19.7)

There was a significant, positive trend reflecting higher odds of breast cancer with increasing maternal o,p'-DDT concentration (p=0.048).
Results Comments
Maternal history of breast cancer was a strong predictor of daughters’ breast cancer. The authors add that other environmental exposures correlated with DDT should not be ignored as possible breast cancer risk factors.
Author address
Child Health and Development Studies, 1683 Shattuck Avenue, Suite B, Berkeley, CA 94709, USA. bcohn@chdstudies.org
Reviewers Comments
The authors do not specify if they considered adjusting the analysis for additional breast cancer risk factors specific to daughters.