Cost-effectiveness analysis of the Oncotype DX Breast Recurrence Score® test among node-negative early breast cancer patients in Japan.

BACKGROUND: The Oncotype DX Breast Recurrence Score® test is prognostic for distant recurrence in hormone receptor positive (HR+), human epidermal growth factor 2 negative (HER2-) early-stage breast cancer. It is the only multigene assay able to predict chemotherapy benefit, validated by evidence from randomized controlled trials. Using a Japanese public healthcare payer perspective, a cost-effectiveness analysis was conducted comparing the Oncotype DX® test to clinico-pathological risk assessment in women with node-negative (N0), HR+/HER2- early breast cancer. METHODS: A decision-tree stratified patients according to their Recurrence Score® (RS®) result and adjuvant chemotherapy allocation. A Markov model was used to capture lifetime costs and outcomes of the chosen treatment. Distributions of clinical risk in N0 patients were derived from the TAILORx trial. Distant recurrence probability conditional on RS result was calculated using TAILORx and NSABP-20 studies. Endocrine and chemoendocrine therapy selection was informed by a Clinical Expert Survey and the literature. Drugs and medical device costs were obtained from the Ministry of Health, Labour and Welfare. RESULTS: The Oncotype DX test was dominant (i.e. cost-saving and more effective) as it generated more quality-adjusted life-years (QALYs) (0.207) at a lower cost (-¥649,596) compared to clinico-pathological risk assessment in the overall population. Cost savings were primarily driven by a lower incidence of distant recurrence (-¥1,007,177). The Oncotype DX test was dominant in all subgroups except for one, which was cost-effective. CONCLUSIONS: Use of the Oncotype DX test to guide treatment decisions improves patient outcomes while reducing healthcare costs for N0 HR+/HER2- early-stage breast cancer in Japan.