EDRI Federal Project Inventory:
70536-01 Phytoestrogens and Breast Cancer–A Pilot Study
- Sponsor Organization: NIH/NCI
- Project Title: 70536-01 PHYTOESTROGENS AND BREAST CANCER--A PILOT STUDY
- Project Focus: EXPOSURE ASSESSMENT
- Description: Phytoestrogens (isoflavonoids and lignans) have anti-estrogenic and
tumor growth inhibition properties. The long-term objective of this
research is to assess whether these compounds protect against breast
cancer. The specific aim ofthis study is to assess the long-term
reliability of serum measurements of phytoestrogens in order to
adequately plan anepidemiologic study in which serum samples from
participants in an ongoing case-control study of breast cancer will
beassayed for phytoestrogens. The case-control study is nested within
a prospective cohort, the New York University(NYU) Women's Health
Study, and serum samples were collected prior to diagnosis and frozen
for future biochemicalanalyses. For a subset of the cohort, repeated
serum samples were collected at approximately yearly intervals.
Dataon the reliability of serum measurements of phytoestrogens is
needed to select the optimum design with respect tosample size and
number of samples/participants in the projected epidemiologic study.
The optimum design will be theone which minimizes the error in
measurement bias (systematic underestimation) commonly observed in
studies of theassociation of serum nutrients with disease risk. The
reliability coefficients will also be used in the analysis of the
case-control study to correct relative risk estimates for residual
exposure error measurement. The study will use the sameresource that
will be used in the epidemiologic study of the association of
phytoestrogens with breast cancer, i.e. theNYU Women's Health Study
bank of frozen serum samples. The samples were collected between 1985
and 1991 from14,291 healthy women who have been actively followed-up
for breast and other cancers ever since. For a subset of the
participants (approximately 25 percent), three or more repeated serum
samples (up to 8), collected at approximatelyyearly intervals, are
available. Thirty-two women (16 pre- and 16 post-menopausal at
blood donation) will beselected at random among participants who
contributed at least three blood donations and who are not included in
any ofthe currently ongoing case-control studies nested within this
cohort. For each of these women, three serum samples willbe retrieved
from the serum bank and assayed for four phytoestrogens:
enterolactone and enterodiol, the two mainhuman lignans, and daidzein
and genistein, the two main human isoflavonoids. The corresponding
reliabilitycoefficients will be calculated. The study will also
assess whether factors such as age, menopausal status and
frozenstorage time affect serum levels of phytoestrogens. Between and
within laboratory batch variability will also beestimated.
- References:
- Category: METHODS
- Subcategory: EXPOSURE AND RISK MODELS
- Keywords for Experimental System/Species: HUMAN
- Keywords for Experimental Endpoints: EXPOSURE MONITORING, EPIDEMIOLOGY
- Chemical Agents: PHYTOESTROGENS
- Performing Institution: NEW YORK UNIVERSITY
- Contact: CONTRACT PERSON: ELAINE C. LEE; BUILDING 31; 11A21; NATIONAL CANCER
INSTITUTE, NIH,BETHESDA, MD 20892-2590; 301-496-5515;
LEEE@OD.NCI.NIH.GOV
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