Genetic Abnormalities in Breast Cancer Tumors and Relationships to environmental and Genetic Risk Factors Using Twins
Abstract
Activities included 1) acquisition of archived tissue blocks on breast cancer concordant twin pairs (205 Mz and 129 DZ) and discordant pairs (550 Mz); 2) immunohistochemistry to detect the level of expression of' biomarkers (p53, HER-2/neu, ER, and PR) in the tumor tissue; 3) DNA sequencing of the p53 gene; 4) FISH to detect amplification of HER-2/neu; and 5) analysis of the association of environmental and genetic factors with the development of these markers. Blocks from 488 twins (254 in concordant pairs and 234 in discordant pairs) have been received. Based on 46 concordant pairs, intra-pair analyses showed that ER was the biomarker most likely to be identical within the pair (Kappa=O.43) and HER-2/neu was the least likely (Kappa=-0.07). The low agreement suggests that environmental factors are likely to play a role in the development of some of these tumor markers. DNA sequencing of the p53 gene has been completed for 67 cases, with 16 having at least one mutation. FISH has been completed on 81 cases. The FISH results were in high agreement with the HER-2/neu IHC results; however the p53 mutation results were not correlated with the p53 IHC results. Analysis of risk factors showed that late menarche and smoking were associated with the development on an ER+ or PR+ tumor; whereas OC use was protective.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1999
- Accession Number
- ADA389338
Entities
People
- Thomas M. Mack
Organizations
- University of Southern California