For women with hormone receptor-positive breast cancer, treatment with aromatase inhibitors (alone or after several years of tamoxifen) lowers the risk of:

• Breast cancer recurrence;
• Breast cancer in the opposite breast; and
• Death from breast cancer.

Among postmenopausal women with hormone receptor-positive breast cancer, aromatase inhibitors (alone or after tamoxifen) offer the same or slightly greater benefit compared to tamoxifen alone. Two aromatase inhibitors (exemestane and anastrozole) have been found to reduce breast cancer in postmenopausal women at increased risk of the disease.

Sources:

American Cancer Society, 2021. Aromatase Inhibitors for Lowering Cancer Risk.

National Cancer Institute, 2022. Hormone Therapy for Breast Cancer.

Susan G. Komen, 2024. Aromatase Inhibitors.