Plasma levels of dichlorodiphenyldichloroethene (DDE) and dichlorodiphenyltrichloroethane (DDT) and survival following breast cancer in the Carolina Breast Cancer Study.

Abstract

OBJECTIVES:

To examine plasma levels of dichlorodiphenyldichloroethene (DDE) and dichlorodiphenyltrichloroethane (DDT) in association with survival among women with breast cancer who participated in a population-based case-control study.

METHODS:

Participants included 456 white and 292 black women from the Carolina Breast Cancer Study Phase I who were diagnosed with primary invasive breast cancer from 1993 to 1996, and who had available DDE/DDT and lipid measurements from blood samples obtained on average 4.1 months after diagnosis. Using the National Death Index, we identified 392 deaths (210 from breast cancer) over a median follow-up of 20.6 years. We used Cox regression to estimate covariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and breast cancer-specific 5-year mortality, and 20-year mortality conditional on 5-year survival, for lipid-standardized DDE and DDT levels. Associations stratified by race and estrogen receptor (ER) status were also examined.

RESULTS:

The highest versus lowest DDE tertile and the highest vs non-detectable DDT quantile were associated with HRs of 1.95 (95% CI = 1.31-2.92) and 1.64 (95% CI = 1.10-2.44), respectively, for 20-year conditional all-cause mortality. DDE levels above versus below the median were associated with a HR of 1.69 (95% CI = 1.06-2.68) for 20-year conditional breast cancer-specific mortality among women overall, and HRs were 2.36 (95% CI = 1.03-5.42) among black women and 1.57 (95% CI = 0.86-2.89) among white women (PInteraction = 0.42), and 3.24 (95% CI = 1.38-7.58) among women with ER- tumors and 1.29 (95% CI = 0.73-2.28) among women with ER+ tumors (PInteraction = 0.03).

CONCLUSION:

Exposure to DDE/DDT may adversely impact overall and breast cancer-specific survival. DDE exposure may contribute to the racial disparities in breast cancer survival.

• Authors: Humberto Parada Jr, Xuezheng Sun, Chiu-Kit Tse, Lawrence S Engel, Andrew F Olshan, Melissa A Troester
• Journal: Environment international (Environ Int) Vol. 125 Pg. 161-171 (04 2019) ISSN: 1873-6750 [Electronic] Netherlands
• PMID: 30716576 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.

Chemical References

• Pesticides
• Dichlorodiphenyl Dichloroethylene
• DDT

Topics

• Black or African American
• Breast Neoplasms (blood, etiology, mortality)
• Cancer Survivors
• Case-Control Studies
• DDT (blood, toxicity)
• Dichlorodiphenyl Dichloroethylene (blood, toxicity)
• Female
• Humans
• Middle Aged
• North Carolina
• Pesticides (blood, toxicity)
• Proportional Hazards Models
• Survival Analysis
• White People