title: Association of 21-gene recurrence score assay and adjuvant chemotherapy use in the medicare population, 2008-2011.
abstract: OBJECTIVE
  The 21-gene recurrence score (RS) assay helps guide adjuvant chemotherapy use for patients with breast cancer, and is predicted to reduce overall chemotherapy use. Little is known about recent patterns of testing in the Medicare program and the impact of testing on chemotherapy use as a function of patient age.
  
  
  METHODS
  We conducted a national claims-based study of Medicare beneficiaries age ≥ 66 years. We assessed trends in assay use (using multivariable regression), adjuvant chemotherapy use, and associated expenditures, for all patients and for two age strata: age 66-74 years and 75-94 years. Geographic variations in assay adoption and regional-level correlation between assay and chemotherapy use were measured.
  
  
  RESULTS
  We identified 132,222 women who underwent breast surgery from 2008-2011. Assay use increased from 9.0% to 17.2% from 2008-2011 (p<.001), but chemotherapy use remained stable at 12.5% (p=.49). In younger patients, assay use increased from 14.3% to 23.7% (p<.001), while chemotherapy use decreased from 18.2% to 16.2% (p<.001). In older patients, assay use increased from 4.1% to 9.9% (p<.001), while chemotherapy use remained stable at 6.8% (p=.67). Mean per-beneficiary expenditures for testing and chemotherapy increased from $2030 to $2430 (p<.001). Regions with increased assay adoption were not more likely to reduce chemotherapy.
  
  
  CONCLUSIONS
  Despite increased RS testing for both younger and older Medicare patients, there has only been a modest decrease in chemotherapy use for younger patients and no change for older patients, resulting in an overall increase in costs associated with gene expression profiling.
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Su
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Section of General Internal Medicine, Yale University School of Medicine, PO Box 208025, New Haven, CT 06520-8025, United States.
authors.forename: Jane
authors.initials: J
authors.lastname: Hall
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Section of General Internal Medicine, Yale University School of Medicine, PO Box 208025, New Haven, CT 06520-8025, United States.
authors.forename: Pamela R
authors.initials: PR
authors.lastname: Soulos
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Yale Cancer Center, Yale University School of Medicine, PO Box 208028, New Haven, CT 06520-8028, United States.
authors.forename: Maysa M
authors.initials: MM
authors.lastname: Abu-Khalaf
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Yale Cancer Center, Yale University School of Medicine, PO Box 208028, New Haven, CT 06520-8028, United States; Department of Therapeutic Radiology, Yale University School of Medicine, PO Box 208040, New Haven, CT 06520-8040, United States.
authors.forename: Suzanne B
authors.initials: SB
authors.lastname: Evans
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Yale Cancer Center, Yale University School of Medicine, PO Box 208028, New Haven, CT 06520-8028, United States.
authors.forename: Sarah S
authors.initials: SS
authors.lastname: Mougalian
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Department of Therapeutic Radiology, Yale University School of Medicine, PO Box 208040, New Haven, CT 06520-8040, United States.
authors.forename: Charles E
authors.initials: CE
authors.lastname: Rutter
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Yale Cancer Center, Yale University School of Medicine, PO Box 208028, New Haven, CT 06520-8028, United States; Yale School of Public Health, Yale University, 60 College Street, P.O. Box 208034, New Haven CT, 06520-8034, United States.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Davidoff
authors.affiliation: Cancer Outcomes, Public Policy, and Effectiveness Research (COPPER) Center, Yale Comprehensive Cancer Center and Yale University School of Medicine, Harkness Office Building, 367 Cedar Street, New Haven CT, 06510, United States; Section of General Internal Medicine, Yale University School of Medicine, PO Box 208025, New Haven, CT 06520-8025, United States; Yale Cancer Center, Yale University School of Medicine, PO Box 208028, New Haven, CT 06520-8028, United States. Electronic address: cary.gross@yale.edu.
authors.forename: Cary P
authors.initials: CP
authors.lastname: Gross
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D003365:Costs and Cost Analysis; D005260:Female; D020869:Gene Expression Profiling / Q000191:economics*; D006801:Humans; D006278:Medicare / Q000191:economics*; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000453:epidemiology / Q000235:genetics*; D014481:United States / Q000453:epidemiology
keywords: Adjuvant; Aged; Breast neoplasms; Chemotherapy; Gene expression profiling; Medicare