Cost-effectiveness of 21-gene assay in node-positive, early-stage breast cancer

To assess impact on health outcomes and healthcare expenditures of adopting a 21-gene assay for women with early-stage, minimally node-positive, estrogen receptor-positive (N (1-3)/ER) HER2-negative breast cancer. We adapted a deterministic decision-analytic model to estimate costs and quality-of-life outcomes associated with chemotherapy, adverse events, supportive care, recurrence, and second primary cancers for usual care compared with care determined by the 21-gene assay recurrence score, where 71% and 54% of women, respectively, were treated with adjuvant chemotherapy. Model input data were based on national statistics, published literature, physician surveys, and Medicare Part B prices. Annual numbers of events were multiplied by quality-adjusted life-years (QALYs) lost and costs to estimate net health and economic impacts of each strategy. Analyses were from a managed care payer perspective for the US population. Patients receiving the assay were predicted to gain 0.127 QALY and save $4359 annually from avoiding chemotherapy, adverse events, supportive care, and secondary primary tumors. For a 2-million member plan, net gains were 4.44 QALYs/year and savings were $13,476/year. Cost savings were greater for the Medicare population. Although overall results were sensitive only to reduced impact of testing and chemotherapy costs, they were still highly cost-effective (incremental cost-effectiveness ratio