title: Impact of Consensus Guidelines by the Society of Surgical Oncology and the American Society for Radiation Oncology on Margins for Breast-Conserving Surgery in Stages 1 and 2 Invasive Breast Cancer.
abstract: BACKGROUND
  This study aimed to evaluate the impact that the release of consensus guidelines for margins in breast-conserving surgery (BCS) had on re-excision rates.
  
  
  METHODS
  A retrospective review examined a prospectively maintained database of patients who had operable invasive breast cancer treated with BCS at the authors' institution. The patients were divided into two groups: (1) those with a diagnosis determined from 1 July 2011 to 31 July 2013 (before release of the guidelines) and (2) those with a diagnosis determined from 1 February 2014 to 31 July 2014 (after release of the guidelines). The groups were evaluated with respect to patient and tumor characteristics, re-excision rates, and reasons for re-excision.
  
  
  RESULTS
  A total of 846 cases of BCS were managed: 597 in group 1 and 249 in group 2. Re-excision rates were significantly reduced after release of the consensus guidelines (p = 0.03). Re-excisions were performed for 115 (19 %) of 597 patients in group 1 and 32 (13 %) of 249 patients in group 2. After release of the guidelines, re-excisions were performed for positive margins, as defined by the consensus statement, in 25 (78 %) of 32 cases. The two groups did not differ significantly in terms of age, tumor size, grade, nodal status, estrogen receptor status, progesterone receptor status, or human epidermal growth factor receptor 2 status. Group 1 had more tumors of mixed ductal and lobular histology than group 2, and group 2 had more lobular tumors than group 1 (p = 0.02).
  
  
  CONCLUSIONS
  The consensus guidelines on margins for BCS were applied for 78 % of the patients who underwent re-excision and resulted in a significant reduction in re-excision rates.
authors: Division of Surgical Oncology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA. alice.chung@cshs.org.
authors: A
authors: A
authors: Chung
authors: Division of Surgical Oncology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors: A
authors: A
authors: Gangi
authors: Division of Surgical Oncology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors: F
authors: F
authors: Amersi
authors: Department of Pathology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors: S
authors: S
authors: Bose
authors: Department of Biostatistics, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors: X
authors: X
authors: Zhang
authors: Division of Surgical Oncology, Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
authors: A
authors: A
authors: Giuliano
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D018275:Carcinoma, Lobular / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D003245:Consensus Statements as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D015412:Mastectomy, Segmental; D008495:Medical Oncology; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D018365:Neoplasm, Residual / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D017410:Practice Guidelines as Topic / Q000592:standards*; D011379:Prognosis; D011446:Prospective Studies; D018787:Radiation Oncology / Q000592:standards; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human