Prospective study of the decision-making impact of the Breast Cancer Index in the selection of patients with ER+ breast cancer for extended endocrine therapy.

Abstract

538 Background: The Breast Cancer Index (BCI) has been validated to quantify an individualized risk of late recurrence and to predict likelihood of benefit from extended endocrine therapy in ER+ early stage breast cancer.The purpose of this study was to prospectively assess the impact of BCI i) to change treatment recommendations regarding extended endocrine therapy, and ii) to examine its effects on patient anxiety and decision conflict. Methods: Patients with stage I-III, ER+ breast cancer treated at the Yale Cancer Center who completed at least 3.5 yrs of adjuvant endocrine therapy were prospectively enrolled over 6 months in 2014. BCI was performed on FFPE samples from the original biopsy (bioTheranostics Inc.). Patients and physicians completed pre- and post-test questionnaires. Patients completed the Traditional Decisional Conflict Scale (DCS) and State Trait Anxiety Inventory Form Y (STAI) pre- and post-test. Results: 100 patients[mean age 61y (45-88), 80% postmenopausal, 57% stage I] were included...