Breast cancer treatment and cardiometabolic effects: The role of menopausal status
In a separate analysis, Dr. Greenlee and colleagues looked at the association between endocrine therapies and cardiometabolic risk based on menopausal status.
Endocrine therapy is associated with CVD in breast cancer survivors and may be associated with developing cardiometabolic risk factors like diabetes, dyslipidemia, and hypertension, they noted, explaining that tamoxifen has mixed estrogenic and antiestrogenic activity, while aromatase inhibitors deplete endogenous estrogen.
Since most studies have compared tamoxifen with aromatase inhibitor use, it has been a challenge challenging to discern the effects of each, Dr. Greenlee said.
She and her colleagues reviewed records for 14,942 breast cancer survivors who were diagnosed between 2005 and 2013. The patients had a mean age of 61 years at baseline, and 24.9% were premenopausal at the time of diagnosis. Of the premenopausal women, 27.3% used tamoxifen, 19.2% used aromatase inhibitors, and 53.5% did not use endocrine therapy, and of the postmenopausal women, 6.6% used tamoxifen, 47.7% used aromatase inhibitors, and 45.7% did not use endocrine therapy.
After adjusting for baseline demographics and health factors, the investigators found that:
- The use of tamoxifen or aromatase inhibitors was not associated with a risk of developing diabetes, dyslipidemia, or hypertension in premenopausal women, or with a risk of developing diabetes or hypertension in postmenopausal women.
- The risk of dyslipidemia was higher in postmenopausal aromatase inhibitor users, and lower in postmenopausal tamoxifen users, compared with postmenopausal non-users of endocrine therapy (HRs, 1.15 and 0.75, respectively).
The lack of associations between endocrine therapy and CVD risk in premenopausal women may be from low power, Dr. Greenlee said, noting that analyses in larger sample sizes are needed.
She and her colleagues plan to conduct further analyses looking at treatment dosage and duration, and comparing steroidal versus nonsteroidal aromatase inhibitors.
Future studies should examine the implications of these associations on long-term CVD and how best to manage lipid profiles in postmenopausal breast cancer survivors who have a history of endocrine therapy treatment, they concluded.
This research was funded by grants from the National Cancer Institute.