Cost‐benefit of the 21‐gene Breast Cancer Recurrence Score Assay for Patients in Singapore

To the Editor: Breast cancer is the most common cancer in women worldwide, with an incidence in Singapore of approximately 55 cases per 100,000 women (1). More than 50% of newly diagnosed patients have early-stage breast cancer (ESBC). Appropriate postoperative therapy may include systematic treatment such as hormone therapy, with or without adjuvant chemotherapy (aCT). Patients in Singapore pay for treatment from a health savings account, referred to as Medisave. As such, women with ESBC must weigh carefully and directly the costs of all tests and services against the potential benefits and toxicities/inconveniences of aCT. The 21-gene recurrence score assay (Oncotype DX Breast Cancer Assay, Genomic Health, Inc., Redwood City, CA, USA) is a clinically validated gene-expression molecular assay that estimates distant recurrence risk and response to aCT (2,3). The study aim is to evaluate the cost-benefit of the recurrence score assay to a Singaporean woman with recently diagnosed estrogenreceptor-positive (ER+) ESBC. The perspective considers both direct medical costs and indirect costs that reflect loss of work productivity associated with aCT administration. Details about the analytical framework and data sources are available in supplementary materials. The recurrence score assay provides a woman with an individual estimate of her risk of distant recurrence and response to aCT. A woman classified as “lowrisk” who might have contemplated aCT before testing may decide instead to forego aCT. A woman classified as “high risk” who might have contemplated no aCT before testing may decide instead to undergo aCT. Weighted direct average cost of chemotherapy drugs, supportive care, chemotherapy administration, and management of adverse events were obtained from Tan Tock Seng Hospital and Johns Hopkins International Medical Centre Singapore. Treatment patterns of these hospitals show that 80% of patients would receive docetaxel plus cyclophophamide and 20% of patients would receive doxorubicin and cyclophosphamide followed by paclitaxel in a dose dense regimen. The cost of recurrence was associated with managing metastatic breast cancer, including 10 cycles of palliative chemotherapy. Between 40% and 50% of women are treated with adjuvant chemotherapy in the published clinical utility studies on the recurrence score assay; similar treatment rates have been observed in Singapore (2–5). Extensive sensitivity analyses were performed to assess the impact of different variables on the cost-benefit of RS. With the recurrence score assay, the likelihood of receiving aCT decreases 21% for a representative Singaporean woman with ER+ ESBC. She would save a net of $5,948 SGD (Singapore dollars) in costs associated with chemotherapy drugs, supportive care, management of adverse events, administrative costs, and management of distant recurrence (Table 1). In addition, the patient would save $1,963 SGD by avoiding productivity losses—approximately 8 days of wages—associated with aCT administration and adverse events. The net cost-saving, accounting for the cost of the assay offset by these reductions in direct and indirect costs, is $2,345 SGD. The most influential drivers of the cost-impact associated with the recurrence score assay were (a) relative risk reduction in recurrence associated with aCT, (b) direct cost of aCT, and (c) the likelihood of being classified as low risk. The appropriate aCT decision is traditionally based on clinical and pathologic characteristics. In Singapore, where each patient is primarily responsible for covering her health care expenditures through out-of-pocket payments and her health savings account, the recurrence score assay helps a woman with ER+ ESBC appropriately allocate available resources and assists physicians in the shared decision-making process. Use of the recurrence score assay can reduce the average Address correspondence and reprint requests to: John Hornberger, MD, MS, 3715 Haven Avenue, Suite 100, Menlo Park, CA 94025, USA, or e-mail: ujch@stanford.edu. Sponsor: Genomic Health, Inc.