Environment and Breast Cancer: Science Review

Evidence From Humans
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Cancer mortality and environmental exposure to DDE in the United States
Cocco, P., Kazerouni, N., Zahm, S. H. Environ Health Perspect. 2000. 108:1, 1-4.
Topic area
Environmental pollutant - Pesticides, organochlorine, DDT, DDE
Study design
Other: Ecologic epidemiology
Study Participants
Menopausal Status
The menopausal status of women included in this study is listed here.
Pre menopausal
Post menopausal
Participant selection: Inclusion and exclusion criteria
Criteria used to select participants in the study.
States with US EPA 1968 DDE monitoring data
Exposures investigated
1968 US EPA human monitoring data for average DDE level by state and race for 22 states
How exposure was measured
Biological GIS/geographic location
Statistical Analysis
Breast cancer outcome investigated
Mortality from breast cancer from 1975-1994
Ethnic groups with separate analysis
If this study provided a separate analysis by ethnic or racial group, the groups are listed here.
African Americans
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.
Average per capita income, percent of state population living in a metropolitan area, population density, birth rate, abortiona rate per live births
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
Linear regression was used to assess average adipose DDE levels by state.
Strength of associations reported
Average adipose DDE was negatively associated with breast cancer mortality in both African American and white women, although statistical significance was only seen for white women.
Results Comments
Breast cancer mortality depends on both incidence and treatment, and therefore is a less sensitive outcome than incidence rate alone. Most of the known hormonal risk factors for breast cancer (e.g. early age at menarche, late menopause) are not controlled for in this analysis.
To explore the role of DDE, the major and most persistent DDT derivative, in cancer etiology, we examined the association of the 1968 adipose DDE levels of population samples from 22 U.S. states with age-adjusted mortality rates between 1975 and 1994 for multiple myeloma; non-Hodgkin lymphoma (NHL); and cancer of the breast, corpus uteri, liver, and pancreas. Separate analyses were conducted by gender and race. Covariates in the regression models included average per-capita income, percent metropolitan residents, and the population density. Liver cancer mortality increased significantly with adipose DDE levels in both sexes among whites, but not among African Americans. No association was observed for pancreatic cancer and multiple myeloma. Breast cancer mortality was inversely correlated with adipose DDE levels among both white and African American women. Significant inverse correlations were also observed for uterine cancer among white women, whereas no association was observed for African Americans and for NHL among whites (men and women) and African American women. The results for pancreatic cancer, multiple myeloma, NHL, breast cancer, and uterine cancer did not support the hypothesis of an association with past adipose levels of the DDT derivative DDE. The multivariate analysis confirmed most findings. The association between liver cancer and DDE observed among whites, particularly in view of the occurrence of hepatic neoplasms in laboratory animals exposed to DDT, warrants further investigation.
Author address
Institute of Occupational Medicine, University of Cagliari, Cagliari, Italy. coccop@pacs.unica.it