Klesia Pirola Madeira
Federal University of Espirito Santo, Brazil
Title: Breast cancer: Estrogen receptor SNPs as risk markers and hormone receptors expression as therapeutic drivers
Biography
Biography: Klesia Pirola Madeira
Abstract
Breast cancer (BC) is the second leading cause of cancer-related death in US women. The ability to effectively treat patients can be complicated by risk factors including single nucleotide polymorphisms (SNPs) in the estrogen receptor gene (ESR1) and misdiagnosis of hormone receptors expression levels. Recently, single nucleotide polymorphisms in PvuII and XbaI have been discovered in the ESR1 gene. To study the significance of these changes, we analyzed the allelic frequenices of these SNPs in samples isolated from patients with BC. We found higher P and X alleles frequencies in Erα-positive BC. Furthermore, the pp and xx genotypes were found exclusively in patients with HT-TMX responsive BC. Analysis of the expression levels of the ER status in 61 BC cases using SP1 and 1D5 monoclonal antibodies revealed a high concoradance rate (96.7%) betwen both antibodies based on immunohistochemical analysis applying the Allred score. Similar analysis of the PgR status in 53 BC cases revealed that the monoclonal antibodies PgR636 and SP42 were suitable for diagnositic purposes while monoclonal the antibody ab62621 should be excluded due a lack of specifity. Taken together, we have revealed that the P allele is a novel biomaker for BC, confirmed that both the pp and xx genotypes enhance responsiveness to chemotherapy, and identified monoclonal antibodies that improve the accuracy of detecting ER and PgR status in BC patients.