Clinical utility and therapeutic implications of oncotype analysis in patients with breast cancer.
e11084 Background: Oncotype DX is a 21-gene assay developed for early stage, hormone receptor positive breast cancer that generates a Recurrence Score which estimates response to chemotherapy and the likelihood of systemic recurrence at 10 years. It differentiates between patients who would benefit from chemotherapy plus hormonal therapy versus hormonal therapy alone. This study’s goal was to determine if the Recurrence Score affected clinical management at our institution and physicians’ accuracy at predicting Recurrence Scores. Methods: A retrospective review was conducted of 116 breast cancer patients treated over a 7 year period. Clinic notes, pathology reports, and additional relevant information were presented to breast surgeons, oncologists, radiation oncologists, and surgical pathologists. Individual physicians estimated recurrence risks and recommended treatment based on those estimates. The Recurrence Score was revealed and changes in therapeutic recommendations were recorded. Results: Treatment recommendations changed in 43% of patients. 29% had a change from chemotherapy followed by hormone therapy to hormone therapy alone due to a low recurrence score, while 14% initially recommended hormonal therapy were changed to chemotherapy plus hormonal therapy due to an intermediate range score. Surgical oncologists accurately predicted Recurrence Scores 52% of the time, medical oncologists 46%, radiation oncologists 45%, and surgical pathologists 15%. A nested mixed model showed that pathologists were statistically significantly worse at predicting recurrence scores than surgical oncologists, medical oncologists, and radiation oncologists. Conclusions: The Oncotype DX assay changes management of breast cancer patients at our institution, frequently downgrading the intensity of systemic therapy. Clinicians were able to accurately estimate recurrence categories about 50% of the time. We recommend the use of Oncotype DX assay along with assessment of clinicopathologic features of an individual’s disease in eligible patients to enhance the selection of appropriate adjuvant therapy.