biostudies-literatureFigueroa JDIntramural NIH HHSNational Cancer Institute457-466https://www.ebi.ac.uk/biostudies/studies/S-EPMC4989123biostudies-literatureUnknown150(2)Identification of prognostic gene expression signatures may enable improved decisions about management of breast cancer. To identify a prognostic signature for breast cancer, we performed DNA methylation profiling and identified methylation markers that were associated with expression of ER, PR, HER2, CK5/6, and EGFR proteins. Methylation markers that were correlated with corresponding mRNA expression levels were identified using 208 invasive tumors from a population-based case-control study conducted in Poland. Using this approach, we defined the methylation expression index (MEI) signature that was based on a weighted sum of mRNA levels of 57 genes. Classification of cases as low or high MEI scores was related to survival using Cox regression models. In the Polish study, women with ER-poBreast cancer research and treatmentIntegrated analysis of DNA methylation, immunohistochemistry and mRNA expression, data identifies a methylation expression index (MEI) robustly associated with survival of ER-positive breast cancer patients.PMC4989123ZIA CP010126ID0ESTAE2019Yang HMeltzer PGarcia-Closas MSherman MELee MDavis SHorne HNLissowska JFigueroa JDfalseIntegrated analysis of DNA methylation, immunohistochemistry and mRNA expression, data identifies a methylation expression index (MEI) robustly associated with survival of ER-positive breast cancer patients.Identification of prognostic gene expression signatures may enable improved decisions about management of breast cancer. To identify a prognostic signature for breast cancer, we performed DNA methylation profiling and identified methylation markers that were associated with expression of ER, PR, HER2, CK5/6, and EGFR proteins. Methylation markers that were correlated with corresponding mRNA expression levels were identified using 208 invasive tumors from a population-based case-control study conducted in Poland. Using this approach, we defined the methylation expression index (MEI) signature that was based on a weighted sum of mRNA levels of 57 genes. Classification of cases as low or high MEI scores was related to survival using Cox regression models. In the Polish study, women with ER-po2015-01-01T00:00:00Z2015 Apr2026-05-01T18:59:50.961Z2019-03-27T02:20:55ZS-EPMC49891232577392810.1007/s10549-015-3314-6