title: Initial Trends in the Use of the 21-Gene Recurrence Score Assay for Patients With Breast Cancer in the Medicare Population, 2005-2009.
abstract: OBJECTIVE
  In 2006, the Centers for Medicare & Medicaid Services approved coverage for the use of the 21-gene recurrence score (RS) assay in women with early-stage, estrogen receptor-positive, node-negative breast cancers to help guide recommendations for adjuvant chemotherapy. Use of the assay in community settings has not been previously examined in a nationally representative sample of patients.
  
  
  OBJECTIVE
  To examine trends in the use of the RS assay in routine clinical practice in a nationally representative sample of women with breast cancer.
  
  
  METHODS
  Retrospective observational study of Medicare beneficiaries diagnosed with incident breast cancer between 2005 and 2009, as recorded in a Surveillance, Epidemiology, and End Results data set with linked Medicare claims through 2010.
  
  
  METHODS
  Demographic and clinical variables associated with the use of the assay.
  
  
  RESULTS
  A total of 70,802 patients met the study criteria. Use of the RS assay increased from 1.1% in 2005 to 10.1% in 2009 (P < .001). The majority of tests (60.9%) occurred in patients with National Comprehensive Cancer Network-defined intermediate-risk disease (ie, estrogen receptor-positive, node-negative tumors >1 cm). Most patients with other than intermediate-risk disease had borderline indications for testing, including T1b (47.5%) or N1 (26.8%) disease. Testing was associated with younger age, fewer comorbid conditions, higher-grade disease, and being married. Among patients younger than 70 years with intermediate-risk disease, testing rates increased from 7.7% in 2005 to 38.8% in 2009 (P < .001). In multivariable analysis, testing was modestly higher in Northeast than in Western registries (odds ratio, 1.83; 95% CI, 1.49-2.26) but was otherwise not associated with region, local census tract demographic characteristics, black race, location in an urban area, or tumor histologic characteristics.
  
  
  CONCLUSIONS
  The RS assay was adopted quickly in clinical practice after the Medicare coverage decision in 2006, and use appears to be consistent with guidelines and equitable across geographic and racial groups. Factors influencing adoption of the assay and its impact on adjuvant chemotherapy use in clinical practice remain important areas of study.
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina2Duke Cancer Institute, Duke University School of Medicine, Durham, North Carolina3Department of Medicine, Duke University School of Medicine, Durham, North Caroli.
authors.forename: Michaela A
authors.initials: MA
authors.lastname: Dinan
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina.
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Mi
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina2Duke Cancer Institute, Duke University School of Medicine, Durham, North Carolina3Department of Medicine, Duke University School of Medicine, Durham, North Caroli.
authors.forename: Shelby D
authors.initials: SD
authors.lastname: Reed
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina2Duke Cancer Institute, Duke University School of Medicine, Durham, North Carolina3Department of Medicine, Duke University School of Medicine, Durham, North Caroli.
authors.forename: Bradford R
authors.initials: BR
authors.lastname: Hirsch
authors.affiliation: Hutchinson Institute for Cancer Outcomes Research, Public Health Sciences Division and Clinical Research Division, Fred Hutchinson Cancer Research Center, Seattle, Washington5Division of Medical Oncology, Department of Medicine, University of Washington S.
authors.forename: Gary H
authors.initials: GH
authors.lastname: Lyman
authors.affiliation: Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina3Department of Medicine, Duke University School of Medicine, Durham, North Carolina.
authors.forename: Lesley H
authors.initials: LH
authors.lastname: Curtis
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics*; D001943:Breast Neoplasms / Q000208:ethnology / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D016009:Chi-Square Distribution; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods / Q000706:statistics & numerical data / Q000639:trends*; D020022:Genetic Predisposition to Disease; D019983:Guideline Adherence; D054625:Healthcare Disparities; D006801:Humans; D006278:Medicare / Q000706:statistics & numerical data / Q000639:trends*; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016017:Odds Ratio; D010641:Phenotype; D017410:Practice Guidelines as Topic; D010818:Practice Patterns, Physicians' / Q000639:trends*; D011237:Predictive Value of Tests; D044469:Racial Groups; D012111:Residence Characteristics; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D018426:SEER Program; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology
chemical_list: D014408:Biomarkers, Tumor