OBJECTIVES: The Oncotype DX Breast Recurrence Score® test identifies patients with HR+/HER2- early breast cancer who are most likely to benefit from adjuvant chemotherapy and reports a Recurrence Score® (RS) result. Based on the RxPONDER study, postmenopausal women with node-positive tumours (N1, 1-3 axillary lymph modes) and RS results 0-25 can be safely spared chemotherapy. An economic evaluation using a decision model was conducted to estimate the cost-effectiveness of the Oncotype DX^® test compared to clinical risk alone from a healthcare cost perspective in Ontario, Canada in HR+/HER2- node-positive early breast cancer.

METHODS: The economic model consisted of a decision tree to stratify patients according to their RS result and adjuvant treatment choice, and a Markov model to estimate long-term outcomes. The probability of chemotherapy assignment conditional on RS result was obtained from a survey of 9 breast oncologists in Canada. Distant recurrence outcomes were informed using RxPONDER for RS 0-25, and TransATAC and SWOG-8814 for RS 26-100. Short-term adverse events (AEs) and long-term consequences of chemotherapy, acute myeloid leukemia (AML) and congestive heart failure (CHF), were included in the model based on literature sources. Cost inputs were obtained from literature and published unit costs for Ontario and reported in 2020 Canadian dollars (CAD).

RESULTS: The Oncotype DX test was cost-saving (-3,448 CAD) and more effective (0.50 incremental QALYs) compared to using clinical risk alone. The results were driven by reduced costs of chemotherapy (-6,511 CAD) and lifetime treatment costs for AML and CHF linked to chemotherapy (-1,837 CAD). Increased life-years and QALYs were derived from avoiding short-term and long-term chemotherapy AEs.

CONCLUSIONS: Chemotherapy treatment decisions based on the Oncotype DX test can yield substantial cost savings from a Canadian healthcare perspective and improve long-term outcomes of a precision medicine approach to adjuvant treatment.