Breast cancer among Alaska Native women potentially exposed to environmental organochlorine chemicals.
OBJECTIVE
To determine if an increased rate of breast cancer in Alaska Native women is related to their consumption of a subsistence diet that may contain p,p'-dichlorodiphenylethylene (DDE) and polychlorinated biphenyls (PCBs).


METHODS
A retrospective case control design.


METHODS
We analyzed banked serum collected between 1981 and 1987 from 126 Alaska Native women, including 63 case women who subsequently developed breast cancer and 63 age-matched control women who remained cancer-free. Serum was analyzed for DDT, DDE, 13 other chlorinated pesticides, and 28 PCB congeners.


RESULTS
The geometric mean for p,p'-DDE levels among case women was 8.67 ppb (95% Confidence Interval 7.48, 10.04); among control women, the geometric mean was 7.36 ppb (6.53, 8.30). The geometric mean for total PCB levels among case women was 4.55 ppb (3.61, 5.74) and for control women, the geometric mean was 6.10 ppb (4.73, 7.86). Cancer status and total PCB levels varied across ethnicity (i.e., Eskimo, Aleut, and Indian) but DDE levels were uniform among these ethnic groups. Using conditional logistic regression analysis to adjust for potential confounders (e.g., ethnicity, family history of breast cancer, parity), we found an odds ratio of 1.43 (0.46, 4.47) for the highest tertile of DDE exposure and 0.42 (0.07, 2.38) for the highest tertile of total PCB exposure.


CONCLUSIONS
Although the results are limited by small sample size and restricted risk factor information, our findings of higher DDE levels, but lower PCB levels among women with breast cancer are consistent with previous research. Our results confirm exposure to organochlorines among Alaska Native women but do not identify these exposures as a significant risk factor for breast cancer.
Centers for Disease Control and Prevention, National Center for Environmental Health, Division of Environmental Hazards and Health Effects, Health Studies Branch, Atlanta, Georgia 30341, USA. chr1@cdc.gov
Carol H
CH
Rubin
Anne
A
Lanier
Stephanie
S
Kieszak
John W
JW
Brock
Kathryn R
KR
Koller
Heather
H
Strosnider
Larry
L
Needham
Shelia
S
Zahm
Annette
A
Harpster
D000413:Alaska / Q000453:epidemiology; D001943:Breast Neoplasms / Q000139:chemically induced / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000009:adverse effects*; D008875:Middle Aged; D044382:Population Groups; D012042:Registries; D012189:Retrospective Studies
D006843:Hydrocarbons, Chlorinated