Breast cancer primary type was predominantly HER- 2 positive (40.3%), among them 5 (8% of total cohort) were ER/PR positive and 20 (32.3% of total cohort) were ER/PR negative; followed by triple negative breast cancer in 29%, luminal B in 22.5% and luminal A in 8% of the BCBM patient cohort. Here, ESR1 is linked to breast cancer.