Utility of the Breast Cancer Index (BCI) in the clinical practice.

Abstract

e14723 Background: Extended endocrine therapy (EET) greater than 5 years in early stage hormone receptor positive (HR+) breast cancer (BC) patients has shown benefit. However, EET is associated with side effects and there is no validated assay to determine which group of patients would derive benefit. Breast Cancer Index (BCI) is a validated bio-marker test that incorporates 2 distinct genomic assays and is prognostic/predictive. The objective of this study is to assess patient characteristics, pathologic features and patient preferences with regards to extending endocrine therapy after reviewing the BCI results. Methods: We performed a retrospective chart review on early stage HR+ BC patients from Jan, 2016 to Jan, 2017 at the University of Vermont Medical Center. We identified 25 cases on whom BCI was submitted. Results: Median age was 68 years. Majority of the patients were stage IA (64%). 56% of the tumors were moderately differentiated. All patients were ER +ve and 12% were HER2+. Median tumor size was 1.4 cm (0.3-4). 76% had poor tolerance to the ET and preferred the test to be sent. In LN-patients, BCI identified 42% as high risk and 52% as low risk for late recurrence and 32% who derive high benefit from EET. In LN+ patients, BCI identified 75% as high risk for late recurrence and 25% as low risk for late recurrence. 40% of the entire group were identified to highly benefit from EET (70% agreed to continue ET and 30% denied due to side effects). Conclusions: BCI is a reasonable test to consider in early stage HR+ BC, especially in patients with poor tolerance to ET. This test might aid in decision making with tolerability/compliance challenges to EET. [Table: see text]