The Breast Cancer Index, which measures estrogen signaling and tumor proliferation, distinguished patients who benefited from ovarian suppression versus those who did not — and the results were unexpected.
Genomic assays are used to determine which patients with early stage, estrogen-receptor–positive (ER+) breast cancer can avoid chemotherapy and to inform the duration of adjuvant endocrine therapy. One such tool, the Breast Cancer Index (BCI), is composed of two biomarker panels: the HOXB13/IL17BR (H/I) gene ratio, which is a measure of estrogen signaling, and the 5-gene Molecular Grade Index, which is a measure of tumor proliferation. Clinical trials have shown that patients with BCI(H/I)-high tumors benefit significantly from extended duration of endocrine therapy after 5 years, while those with BCI(H/I)-low tumors do not.
Another issue, particularly in young, premenopausal women with early-stage breast cancer at high risk for recurrence, …
Reviewing Author
DisclosuresConsultant/Advisory BoardLilly; AstraZeneca; Gilead
Grant/Research SupportBreast Cancer Research Foundation
Editorial BoardsClinical Breast Cancer; Oncology; Annals of Surgery; Breast Cancer Research and Treatment
Leadership Positions in Professional SocietiesNational Comprehensive Cancer Network (Chair, Breast Cancer Panel); American Board of Internal Medicine (Medical Oncology Board)
DisclosuresConsultant/Advisory BoardLilly; AstraZeneca; Gilead
Grant/Research SupportBreast Cancer Research Foundation
Editorial BoardsClinical Breast Cancer; Oncology; Annals of Surgery; Breast Cancer Research and Treatment
Leadership Positions in Professional SocietiesNational Comprehensive Cancer Network (Chair, Breast Cancer Panel); American Board of Internal Medicine (Medical Oncology Board)