Genetic Plymorphisms, Estrogens, and Breast Density
Abstract
This study investigated the association between genetic polymorphisms in hormone producing and metabolizing enzymes and several markers of breast cancer risk among women of different ethnic background. The specific aims were to analyze the relation of breast density and estrogen levels in urine and serum with the presence of variant alleles in CYP17, COMT, CYP1A1, CYP1A2, and CYP1B1, to describe ethnic differences in urinary excretion levels of estrogen, and to explore the association of breast density with estrogen levels. Mammograms for 328 women were assessed for breast density using a computer-assisted method. The genes were analyzed for polymorphisms using PCR/RFLP methods and estrogens and their metabolites were measured by radioimmunoassay. We found that women carrying the COMT and CYP1A2 variant alleles had lower mammographic densities than women carrying the common alleles. The CYP1A2 C allele was also significantly associated with lower serum estradiol levels and a lower 2OHE1/16alpha-OHE1 ratio. Total urinary hormone excretion, androgens, 2-OHE1, and the 2/16alpha-OHE1 ratio were significantly lower in women of Asian ancestry than in Caucasians, but breast density was higher among women of Asian ancestry due to their relatively small breast size. Estrogens and their metabolites measured in the urine of premenopausal women were not associated with mammographic densities. However, contrary to the initial hypothesis, the 2-OHE1/16alpha-OHE1 ratio was directly related with mammographic densities.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2005
- Accession Number
- ADA432441
Entities
People
- Gertraud Maskarinec
Organizations
- University of Hawaiʻi System