Assessment of Adjuvant Endocrine Therapy With Ovarian Function Suppression by Breast Cancer Index

In this study of premenopausal women with hormone receptor-positive breast cancer, BCI (H/I) status did not clearly predict greater benefit of adjuvant exemestane plus OFS vs tamoxifen plus OFS for women with BCI (H/I)-low tumors than for those with BCI (H/I)-high tumors; BCI continuous indices were reconfirmed as prognostic for premenopausal women. These findings support prior results of SOFT, which compared tamoxifen-alone vs OFS with either exemestane or tamoxifen, indicating premenopausal patients with BCI (H/I)-low tumors may benefit from more intensive endocrine therapy.