ESR1 and breast cancer: Interestingly, while it has been recognized that estrogen has a protective effect on cardiovascular system and anti-estrogen therapy may thus negatively impact on that [36, 37], It was also reported correlations between endocrine pathologies as negative prognostic factors both for breast cancer progression and survival [38],our study showed no significant difference in the risk of death from heart diseases between ER or PR positive and negative subgroups.