Chemoprevention of Breast Cancer by Mimicking the Protective Effect of Early First Birth
Abstract
We have successfully shown that in the rat estradiol, estradiol plus progesterone, and beta-HCG is protective against carcinogen-induced mammary tumorigenesis. Progesterone alone was not protective; perphenazine was partially protective. Treatment and pregnancy induced RNA gene expression changes have been identified. Work on finding the lowest effective dose of estrogen has started. We have continued to collect normal breast tissue from women undergoing elective reduction mammoplasty. Estrogen receptor, progesterone receptors and cell proliferation have been characterized and compared to breast tissue obtained from women in the first trimester of pregnancy. RNA characterization of these samples has begun. Two chemoprevention protocols have been developed. The first evaluates the role of high dose progestins on cell proliferation and gene expression profiles in the breast; recruitment is ongoing. The second evaluates the role of various oral contraceptive progestin doses on cell proliferation and gene expression profiles in the breast; recruitment will be complete by the end of October 2008. Pregnancy reduces mammographic density and breast cancer risk. How these are related has been studied in a large autopsy series; results suggest that part of the protection may be the result of a reduction in breast epithelium.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2008
- Accession Number
- ADA492953
Entities
People
- Malcolm C Pike
Organizations
- University of Southern California