Adjuvant systemic treatment of premenopausal women with hormone receptor-positive early breast cancer: lights and shadows

Research has shown premenopausal women with hormone receptor–positive (HR+) early breast cancer who experience chemotherapy-induced amenorrhea (CIA) have reduced risk of recurrence compared with those who have no CIA, whether treated with adjuvant chemotherapy alone or followed by tamoxifen. Younger premenopausal women, in particular those younger than 35 years, are less likely to experience CIA and have increased risk of recurrence. The Suppression of Ovarian Function Trial (SOFT) tested whether women with HR+ breast cancer who remained premenopausal after chemotherapy, and those never receiving chemotherapy, benefit from adding ovarian function suppression (OFS) to 5 years of tamoxifen treatment, or from use of the aromatase inhibitor (AI) exemestane with OFS. The companion Tamoxifen and Exemestane Trial (TEXT) tested the benefit of exemestane versus tamoxifen for women receiving adjuvant OFS, with or without chemotherapy.