Cost–Utility Analysis of 21-Gene Assay for Node-Positive Early Breast Cancer

Background For women with lymph node (LN)–positive, estrogen receptor–positive, and her2 (human epidermal growth factor receptor 2)–negative breast cancer (BCa), current guidelines recommend treatment with both hormonal therapy and chemotherapy. The 21-gene Recurrence Score (RS) assay might be helpful in selecting patients with bca who can be spared chemotherapy when they have 1–3 positive lns and a lower risk of recurrence. In the present study, we performed a cost–utility analysis comparing use of the 21-gene rs assay with current practice from the perspective of a Canadian health care payer. Methods A Markov model was developed to determine costs and quality-adjusted life-years (QALYS) over a patient’s lifetime. Patient outcomes in both study groups were examined based on published clinical trials. Costs were derived primarily from published Canadian sources. Costs and outcomes were discounted at 1.5% annually, and costs are reported in 2016 Canadian dollars. A probabilistic analysis was used, and the model parameters were varied in a sensitivity analysis. Results The results indicate that use of the 21-gene rs assay was less costly ($432 less) and more effective (0.22 qalys) than current practice. The probabilistic analysis revealed that 70% of the 10,000 simulated incremental cost-effectiveness ratios were in the southeast quadrant. The results were sensitive to the probability of a low rs and to the probability of receiving chemotherapy in the low-risk rs category and in current practice. Conclusions Use of the 21-gene rs assay could be a cost-effective strategy for Ontario patients with estrogen receptor–positive, HER2-negative early bca and 1–3 positive LNS.