Beyond the guidelines: Clinical investigators' (CI) self-reported use of genomic assays (GA) to assist in decision-making regarding use of neoadjuvant (NA) and adjuvant chemotherapy for patients (pts) with ER-positive/HER2-negative (ER+/HER2-) early breast cancer (BC).
e18187 Background: GA, specifically the 21-gene Recurrence Score (RS), have been widely used to help inform decisions regarding use of adjuvant chemotherapy in ER+/HER2- node-negative BC. Although substantial anecdotal evidence exists that clinicians, particularly BC-focused CI, are employing these tests in other situations (node-positive disease, the NA setting), ASCO guidelines do not endorse these practices. Here we aimed to quantify self-reported CI use of GA across a spectrum of hypothetical BC presentations. Methods: In December 2016, a 225-item survey was sent to 97 US-based surgical (S) and medical oncology (MO) CI from a proprietary database. A modest honorarium was provided. Results: 51 CI (26 S and 25 MO) completed the survey. CI generally recommend GA for node-negative tumors but less so for older pts with smaller lesions. 75% of CI reported that they would recommend GA for pts with 1 involved node and 55% would do so for those with 2 to 3 nodes. 31% of CI use GA to guide NA chemotherapy decisions, and 53% who do not use GA in NA decision-making altered their treatment approach when a GA result was available. Conclusions: CI prefer GA when the benefit of chemotherapy is uncertain based on tumor stage and pt age. CI are comfortable using GA in node-negative and node-positive hypothetical cases, and some do so to aid in decisions regarding NA therapy. Quantitative assessment of self-reported CI practice patterns can serve as a complement to established guidelines and provide physicians, pts and third-party payers additional viewpoints on possible appropriate management strategies. [Table: see text]