Utilization of oncotype DX in node-negative, ER-positive breast cancer patients

Abstract

11067 Background: The 21 gene RT-PCR assay Oncotype DX (Genomic Health, CA) stratifies patients into low, intermediate and high risk for systemic recurrence. The objective of this study was to examine the patterns of use of Oncotype DX in a single institution. Methods: All patients who had ODX testing requested by the University of Pennsylvania were identified and recurrence scores (RS) obtained. Patient and tumor characteristics, as well as treatment administered, were obtained by chart review for analysis. Results: 100 ODX tests were ordered between 1/1/05–11/30/06. RS results classified 51% of breast cancers as low risk, 38% intermediate risk, and 11% high risk. Characteristics of the tumors of the overall population and by RS group are shown in Table . 99% of patients received hormonal therapy. Of the low risk patients, only one patient was treated with chemotherapy (2%) while 34% of the intermediate risk group and 80% of the high risk group received chemotherapy. Notably, only 4/100 patients with ODX were under age 35 and 17/100 had tumors over 2cm. Conclusions: In this series, ODX use is accelerating. The results of the ODX tests appear to be used clinically as demonstrated by the very low use of chemotherapy in the low risk group. Comparison to the overall population of ER positive, node negative patients seen at this institution is underway. [Table: see text] No significant financial relationships to disclose.