OBJECTIVES: Risk classification tools such as the Nottingham Prognostic Index (NPI) and PREDICT use clinicopathologic factors to inform decisions on the use of adjuvant chemotherapy in HR+/HER2- early-stage breast cancer. The Oncotype DX® test provides additional information beyond clinicopathologic factors on the likely benefit of chemotherapy. Audit data for the Oncotype DX test in Germany suggests that 17% of patients with grade 2 T1c (G2T1c) node negative tumours, categorised as low-risk using NPI or PREDICT, are likely to benefit from adjuvant chemotherapy. An existing model was adapted to estimate the cost-effectiveness of the Oncotype DX test in comparison to clinicopathologic risk assessment alone to guide chemotherapy decisions in this subgroup.

METHODS: A decision-tree model stratified patients according to their Recurrence Score® (RS) result based on the TAILORx study and audit data. The probability of receiving chemotherapy with and without the Oncotype DX test was obtained from the Clalit registry and the UK National Cancer Registration and Analysis Service (NCRAS). A Markov state transition model estimated distant recurrence and survival over a lifetime horizon based on the results from the RSClin^TM tool, which integrates data from the TAILORx, NSABP-14 and NSABP-20 studies. The incremental cost-effectiveness ratio (ICER) for the Oncotype DX test compared to clinicopathologic risk assessment alone was presented from a UK NHS and personal social services perspective.

RESULTS: Compared to clinicopathologic risk assessment alone, the Oncotype DX test was more effective (0.09 incremental QALYs) and more costly (£1,894), with a base case ICER of £20,767.

CONCLUSIONS: The current analysis demonstrates that the Oncotype DX test has the potential to be a cost-effective addition to existing clinical risk-informed stratification tools to inform adjuvant treatment decisions for node negative G2T1c patients. Reducing under-treatment increases quality and length of life and reduces the need for costly treatments in future life-years.