Do endocrine treatments for breast cancer have a negative impact on lipid profiles and cardiovascular risk in postmenopausal women?

Although cardiovascular disease occurs infrequently in premenopausal women, the incidence increases dramatically after menopause. Endocrine agents used to treat postmenopausal women with breast cancer further reduce estrogen levels and have the potential to adversely affect lipid metabolism, although the relevance of this to cardiovascular risk remains uncertain. Until recently, the standard endocrine treatment for breast cancer was tamoxifen, which appears to have a generally favorable effect on lipid parameters, although this does not translate into cardioprotective effects. The third-generation aromatase inhibitors (AIs), including anastrozole, have recently emerged as alternatives for the treatment of postmenopausal women with hormone-sensitive breast cancer. Anastrozole, currently the only AI with established long-term safety data in the adjuvant setting, results in significantly fewer thromboembolic and cerebrovascular events compared with tamoxifen, and a similar incidence of ischemic cardiovascular events. However, the effects of other AIs on lipid values are variable, and any relationship with cardiovascular events in long-term studies is currently unknown.