title: Cost-Savings Analysis of AR-V7 Testing in Patients With Metastatic Castration-Resistant Prostate Cancer Eligible for Treatment With Abiraterone or Enzalutamide.
abstract: Identification of cancer biomarkers that inform clinical decisions and reduce the use of ineffective therapies is a major goal of precision oncology. An abnormal splice variant of the androgen receptor, AR-V7, was recently found to confer resistance to novel hormonal therapies (abiraterone and enzalutamide) in men with metastatic castration-resistant prostate cancer (mCRPC), but did not negatively affect responses to taxane chemotherapies, suggesting that early use of chemotherapy may be a more effective option for AR-V7(+) patients.
  
  
  
  We calculated the cost savings of performing AR-V7 testing in mCRPC patients prior to starting abiraterone/enzalutamide (and avoiding these drugs in AR-V7(+) men) versus treating all mCRPC patients empirically with abiraterone/enzalutamide (without use of the biomarker).
  
  
  
  We determined that AR-V7 testing would result in substantial cost savings as long as the true prevalence of AR-V7 was >5%. In our prior studies, we estimated that approximately 30% of mCRPC patients may have detectable AR-V7 in circulating tumor cells (CTCs). In this population, upfront testing of AR-V7 status (at a price of $1,000 per test) would result in a net cost savings of $150 Million in the United States per year.
  
  
  
  AR-V7 testing in mCRPC patients would be cost-beneficial when considering the current price of treatment, and may reduce the ineffective use of abiraterone/enzalutamide, leading to a significant net cost savings to the healthcare system. Clinical-grade AR-V7 testing is currently available at our institution. Prostate 76:1484-1490, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland. mmarko12@jhmi.edu.
authors.forename: Mark C
authors.initials: MC
authors.lastname: Markowski
authors.affiliation: Johns Hopkins Carey Business School, Baltimore, Maryland.
authors.forename: Kevin D
authors.initials: KD
authors.lastname: Frick
authors.affiliation: Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.|Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: James R
authors.initials: JR
authors.lastname: Eshleman
authors.affiliation: Department of Urology, Brady Urological Institute, Johns Hopkins University, Baltimore, Maryland.
authors.forename: Jun
authors.initials: J
authors.lastname: Luo
authors.affiliation: Department of Oncology, Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland. eantona1@jhmi.edu.|Department of Urology, Brady Urological Institute, Johns Hopkins University, Baltimore, Maryland. eantona1@jhmi.edu.
authors.forename: Emmanuel S
authors.initials: ES
authors.lastname: Antonarakis
mesh_terms: D000736:Androstenes / Q000627:therapeutic use*; D001549:Benzamides; D015415:Biomarkers / Q000032:analysis; D001952:Bridged-Ring Compounds / Q000627:therapeutic use; D017046:Cost Savings; D003365:Costs and Cost Analysis; D019008:Drug Resistance, Neoplasm / Q000235:genetics*; D006801:Humans; D008297:Male; D009362:Neoplasm Metastasis / Q000188:drug therapy; D009570:Nitriles; D010669:Phenylthiohydantoin / Q000031:analogs & derivatives* / Q000627:therapeutic use; D064129:Prostatic Neoplasms, Castration-Resistant / Q000188:drug therapy* / Q000191:economics / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics; D011944:Receptors, Androgen / Q000235:genetics*; D043823:Taxoids / Q000627:therapeutic use
chemical_list: C410798:AR protein, human; D000736:Androstenes; D001549:Benzamides; D015415:Biomarkers; D001952:Bridged-Ring Compounds; D009570:Nitriles; D020033:Protein Isoforms; D011944:Receptors, Androgen; D043823:Taxoids; C080625:taxane; D010669:Phenylthiohydantoin; C540278:enzalutamide; C089740:abiraterone
keywords: AR-V7 testing; CLIA-certified; cost savings; healthcare costs; prostate cancer