Association of promoter methylation of ERα and ERβ with sporadic breast cancer—a study from North India

Methylations in estrogen receptor (ER) α and ERβ are known to be involved in the pathogenesis of breast cancer. Here, we explore the role of promoter methylation of estrogen receptors, ERα and ERβ, in sporadic breast cancer cases from a North Indian population. To this end, association between ERα and ERβ methylation status along with different clinicopathological parameters and its correlation with protein expression was examined. Four hundred eighty paired breast cancer tissue samples and adjacent normal controls from 240 sporadic breast cancer patients were included, and their clinical and demographic profiles were recorded. ERα and ERβ methylation was determined by methylation-specific polymerase (MSP) chain reaction. Our findings demonstrate that methylation of ERα and ERβ occurs in high frequency and appears to be a mechanism of gene silencing in our population. Furthermore, on performing stratified analysis, we observed strong associations between ERα/ERβ methylation and ER, PR, and HER2 status, tumor size, clinical stage, and triple negative tumors. Thus, our study not only highlights the role of ERα/ERβ methylation in breast cancer but also suggests the ERα/ERβ methylation pattern as a biomarker for assessing breast cancer risk.