ESR1 and PGR Gene Promoter Methylation and Correlations with Estrogen and Progesterone Receptors in Ductal and Lobular Breast Cancer

Abstract

The aim of this work was to analyze methylation of the promoter sites of the ESR1 and PGR genes and todetermine correlations with immunohistochemical expression of estrogen and progesterone receptors in ductaland lobular breast cancers. An observational, descriptive, molecular study was conducted on 20 ductal and 20lobular breast cancer samples with immunohistochemical determination of estrogen and progesterone receptorexpression. The methylation analysis of ESR1 and PGR promoter sites was carried-out by methylation-specificPCR. For correlation analysis, Kendall’s tau coefficient was determined. Positive correlations were found betweenestrogen and progesterone receptors, estrogen receptor and unmethylated progesterone receptor, progesteronereceptor, and unmethylated progesterone receptor. Negative correlations were found between estrogen receptorand methylated progesterone receptor, progesterone receptor and methylated progesterone receptor, methylatedand unmethylated estrogen receptor, and methylated and unmethylated progesterone receptor. The resultssuggest that methylation of promoter sites of ESR1 and PGR is a relatively uncommon event in ductal and lobularbreast cancer, and also suggest that the determination of epigenetic states of ESR1 and PGR could represent analternative or complement to the histopathological expression analysis.