Genetic Abnormalities in Breast Cancer Tumors and Relationships to Environmentaland Genetic Risk Factors Using Twins

摘要

Archived tissue blocks are being sought on breast cancer concordant twin pairs(207 MZ and 131 DZ) and on discordant pairs (549 MZ), the presence of selected biomakers (p53, HER-2/neu, ER, and PR) in the tumor tissue is being determined, and the association of environmental and genetic factors with the development of these markers is being investigated. Blocks from 276 twins (200 from concordant pairs and 76 from discordant pairs) have been received. Based on 40 pairs of the concordant twins with completed immunohistochemistry, intra-pair analyses have shown that ER was the bio marker most likely to be identical in the pair (Kappa=0.42) and HER-2/neu was the least likely (Kappa=0.19). The relatively low agreement between members of these pairs suggests that environmental factors are likely to play a role in the development of these tumor markers. Preliminary analyses of the association of breast cancer risk factors with the tumor markers indicated that cases who breast fed were less likely to develop a tumor which expressed p53 than those who did not.