Is circulating tumor cell count-driven cost-effective for first-line therapy choice in HR+/HER2- metastatic breast cancer in the United States?

Background: Circulating tumor cell (CTC) counting may be a useful non-invasive biomarker that helps patients choose first-line treatment options. Nevertheless, the cost of CTC inspection may impose an economic burden on patients, necessitating the simultaneous consideration of both its clinical effectiveness and cost. We evaluated the cost-effectiveness of CTC count-guided chemotherapy and endocrine therapy as first-line therapy for HR+/HER2-metastatic breast cancer (MBC) from the perspective of US payers. Methods: Based on the STIC CTC trial, a Markov model was constructed for three health states, and health outcomes were measured in quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). One-way and probabilistic sensitivity analyses were performed to assess the robustness of the incremental cost per QALY. Results: The base-case analysis revealed that CTC count-driven treatment was associated with improved effectiveness by 0.07 QALYs and increased the overall cost by $9187.05 compared with clinician-driven first-line treatment choices, leading to an ICER of $138 354.15 per QALY. One-way sensitivity analysis indicated that the model was most sensitive to the cost of treatment for neutropenia and the utility for PFS; probability sensitivity analysis indicated that CTC count-driven treatment choices would be considered the cost-effective option at a willingness-to-pay threshold of $150 000 per QALY. Conclusions: The findings of this cost-effectiveness analysis suggest that, at the current price of CTC enumeration, choosing first-line treatment options based on CTC count is a cost-effectiveness approach for treating patients with HR+/HER2- MBC in the US.