Correlation of serum ESR1 methylation levels with RE status in tumor and molecular subtypes of breast cancer

e13648 Background: To determine whether estrogen receptor (ER) (+) and ER (-) status relates to epigenetic changes in breast cancer-related genes and to correlate with molecular breast cancer subtypes. Methods: From January 2002 to June 2005, we quantified methylation levels ERS1 gene in serum of 92 pts breast cancer. A PCR quantitative technique was used to analyze levels of methylation gene. We also examined and correlationed the expression of ESR1 AND HER2+ in tumors by immunohistochemistry with molecular phenotype. Results: Median age was 58 years (32-88); 69% were postmenopausal women. Nodal involvement (N0;63%,N1;30%,N2;7%), tumor size (T1;58%, T2;35%, T3;4%, T4;4%) and grade (G1;20%, G2;37%, G3;30%). Of the cases, 37pts (40%) were Luminal A (LA), 32pts (33%) Luminal B (LB), 14pts (15%) triple-negative (TN), and 9pts (10%) HER2+. The methylated ESR1 in serum was significantly associated with ER(-) in breast tumors >80% (p=0.0179). Methylation ESR1 was preferably associated with TN (80%) and HER2+ (6...