Abstract PO1-01-10: Comparison of the cost-effectiveness of multigene assays for HR+/HER2- node-negative early-stage breast cancer in the US
Authors: Berdunov Vladislav , Carter Gebra Cuyun , Russell Christy , Campbell Sara , Racz Jennifer , Abdou Yara 
Published: May 2024

Abstract
Background Traditional clinico-pathologic features, such as tumor grade and size, age, and menopausal status, may provide incomplete prognostic information, and have limited ability to predict chemotherapy benefit for patients with hormone-receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2)-, axillary lymph node-negative (N0) early-stage breast cancer, leading to both under- and over-treatment with adjuvant chemotherapy. Multigene expression profile tests have been used in clinical practice to complement clinico-pathologic information to optimize treatment decisions. To date, the Oncotype DX Breast Recurrence ScoreÒ test is the only multigene assay with the ability to predict chemotherapy benefit validated by evidence from randomized clinical trials and supported by NCCN and ASCO guidelines. Other commercially available assays in the US include MammaPrintÒ, EndoPredictÒ and Prosigna RORÒ, which offer prognostic information beyond traditional clinico-pathologic features to improve treatment decisions. The relative cost-effectiveness of the four multigene assays compared to using clinico-pathologic risk alone to guide chemotherapy decisions was assessed from a societal perspective in the US. Methods A cost-effectiveness model built in Microsoft Excel estimated the cost-effectiveness of the Oncotype DXÒ test, MammaPrint, EndoPredict and Prosigna ROR compared to using clinical-pathological risk alone over a lifetime horizon. The model structure consisted of a decision-tree portion informed using published studies for the distribution of distant recurrence risk categories as defined by each test (low, intermediate, and high risk for the Oncotype DX test and Prosigna ROR, low and high risk for MammaPrint and EndoPredict). Decision impact studies and clinical expert opinion informed the proportion of patients allocated to adjuvant chemotherapy conditional on test result category. A Markov discrete health state model then simulated the future risk of distant recurrence, and long-term adverse effects of chemotherapy: acute myeloid leukemia (AML), and congestive heart failure (CHF), and aggregated the costs and outcomes of treatment decisions over a patient’s lifetime. The probability of distant recurrence of breast cancer conditional on test result category was derived from the most up-to-date studies assessing the performance of tests: TAILORx for the Oncotype DX test, MINDACT for MammaPrint, and TransATAC for EndoPredict and Prosigna ROR. Costs were estimated from a US societal perspective in 2020 US dollars (including Medicare healthcare costs, lost productivity and patient out-of-pocket chemotherapy costs from literature), and outcomes were expressed in terms of life-years, quality-adjusted life-years (QALYs), and net monetary benefit (NMB). The cost-effectiveness of each multigene assay compared to using clinico-pathologic risk alone was presented using the incremental cost-effectiveness ratio (ICER). Results Using the Oncotype DX test resulted in the largest lifetime cost savings (-$13,395) and generated the largest QALY gain (0.25) out of the four multigene assays included in the model, when compared to using clinico-pathologic risk alone (Table 1). All four multigene assays represented a cost-effective use of resources from a societal perspective (based on the accepted willingness-to-pay threshold of $100,000 per QALY gained), with a low net lifetime cost or net cost savings with positive QALY gain. Conclusion These results support the use of multigene assays to guide treatment decisions in node-negative HR+/HER2- early-stage breast cancer to improve treatment outcomes, and also result in substantial net cost savings from a societal perspective. The prediction of chemotherapy benefit using the Oncotype DX test resulted in substantially higher cost savings and improved breast cancer outcomes.

Citation Format: Vladislav Berdunov, Gebra Cuyun Carter, Christy Russell, Sara Campbell, Jennifer Racz, Yara Abdou. Comparison of the cost-effectiveness of multigene assays for HR+/HER2- node-negative early-stage breast cancer in the US [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-01-10.