title: Margin re-excision and local recurrence in invasive breast cancer: A cost analysis using a decision tree model.
abstract: BACKGROUND
  SSO-ASTRO recently published guidelines defining adequate margins in breast conservation therapy (BCT) as no tumor on ink based on studies demonstrating little difference in local recurrence (LR) with wider margins. We hypothesize that not routinely re-excising close margins results in decreased costs without compromising care.
  
  
  METHODS
  A decision tree model was developed for the management of margins after BCT for invasive cancer. Patients were compared among three margin status groups: positive, close (≤2 mm) and negative (>2 mm). Ten publications provided re-excision rates (RER) and LR rates. The model assumed 140,000 BCT/year. Sensitivity analyses determined the most cost-effective strategy. Surgical costs were estimated using 2013 Medicare reimbursement rates.
  
  
  RESULTS
  Re-excising close margins was significantly more costly than the alternative, $233.1 million versus $214.3 million, per year in the United States. Total surgical cost was most sensitive to re-excision of close margins-increasing the RER from 0% to 100% resulted in an $18.8 million cost difference.
  
  
  CONCLUSIONS
  The strategy of re-excising close margins resulted in a predicted cost of $18.8 million per year. This does not include hospital costs, the cost of surgical complications after re-excision, and underestimates the potential savings by using Medicare reimbursement rates.
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Shoko E
authors.initials: SE
authors.lastname: Abe
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Joshua S
authors.initials: JS
authors.lastname: Hill
authors.affiliation: Department of Cancer Biostatistics, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Yimei
authors.initials: Y
authors.lastname: Han
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Kendall
authors.initials: K
authors.lastname: Walsh
authors.affiliation: Department of Cancer Biostatistics, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: James T
authors.initials: JT
authors.lastname: Symanowski
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Lejla
authors.initials: L
authors.lastname: Hadzikadic-Gusic
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Teresa
authors.initials: T
authors.lastname: Flippo-Morton
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Terry
authors.initials: T
authors.lastname: Sarantou
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Meghan
authors.initials: M
authors.lastname: Forster
authors.affiliation: Division of Surgical Oncology, Department of Surgery, Levine Cancer Institute, Carolinas Medical Center, Carolinas Healthcare System, Charlotte, North Carolina.
authors.forename: Richard L
authors.initials: RL
authors.lastname: White
mesh_terms: D001943:Breast Neoplasms / Q000191:economics* / Q000473:pathology / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000191:economics* / Q000473:pathology / Q000601:surgery; D003362:Cost-Benefit Analysis; D003663:Decision Trees; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015412:Mastectomy, Segmental / Q000191:economics*; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000191:economics* / Q000473:pathology / Q000601:surgery; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000191:economics / Q000473:pathology / Q000601:surgery; D011379:Prognosis; D012086:Reoperation / Q000191:economics*
keywords: breast cancer; breast conservation surgery; cost analysis; decision tree