title: Cost effectiveness of a 21-gene recurrence score assay versus Canadian clinical practice in post-menopausal women with early-stage estrogen or progesterone-receptor-positive, axillary lymph-node positive breast cancer.
abstract: BACKGROUND
  A 21-gene recurrence score (RS) assay provides a method of guiding treatment decisions in women with early-stage breast cancer (ESBC). We investigated the cost effectiveness of using the RS assay versus current clinical practice (CCP) in post-menopausal women with estrogen- or progesterone-receptor-positive, one to three positive axillary lymph-node ESBC from the perspective of the Canadian public healthcare system.
  
  
  METHODS
  We developed a decision analytic model to project the lifetime clinical and economic consequences of ESBC. We assumed that the RS assay would classify patients among risk levels (low, intermediate and high) and corresponding adjuvant treatment regimens. The model was parameterized using 7-year follow-up data from the Manitoba Cancer Registry, cost data from Manitoba Health administrative databases and secondary sources. Costs are presented in 2012 Canadian dollars, and future costs and benefits were discounted at 5 %.
  
  
  RESULTS
  In the base case analysis, the RS assay compared with CCP led to an increase of 0.08 quality-adjusted life-year (QALY) and an increase in cost of Can$36.2 per person, resulting in an incremental cost-effectiveness ratio (ICER) of Can$464/QALY gained. The ICER was most sensitive to the proportion of women classified to intermediate risk by the RS assay who received adjuvant chemotherapy, and absolute risk of relapse among patients receiving the RS assay.
  
  
  CONCLUSIONS
  The RS assay is likely to be cost effective in the Canadian healthcare system. Field evaluations of the assay in this patient population will help reduce uncertainty in clinical guidelines for intermediate-range RS-assay values and specific disease outcomes by the RS assay, which are important drivers of ICER.
authors.affiliation: Department of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, Western University, 1151 Richmond St, London, ON, N6A 5C1, Canada, mbassamh27@gmail.com.
authors.forename: Malek B
authors.initials: MB
authors.lastname: Hannouf
authors.forename: Bin
authors.initials: B
authors.lastname: Xie
authors.forename: Muriel
authors.initials: M
authors.lastname: Brackstone
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Zaric
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000191:economics / Q000627:therapeutic use; D001365:Axilla; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000191:economics* / Q000401:mortality; D002170:Canada; D017024:Chemotherapy, Adjuvant / Q000009:adverse effects / Q000191:economics / Q000379:methods; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D005260:Female; D020869:Gene Expression Profiling / Q000191:economics* / Q000379:methods; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008390:Markov Chains; D008593:Menopause; D008875:Middle Aged; D018803:Models, Economic; D009364:Neoplasm Recurrence, Local / Q000235:genetics; D009367:Neoplasm Staging; D017410:Practice Guidelines as Topic; D019057:Quality-Adjusted Life Years; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D011980:Receptors, Progesterone / Q000096:biosynthesis*; D018570:Risk Assessment
chemical_list: D018931:Antineoplastic Agents, Hormonal; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone