title: The 21-gene recurrence score and locoregional recurrence in breast cancer patients.
abstract: OBJECTIVE
  Although the 21-gene recurrence score (RS) assay has been validated to assess the risk of distant recurrence in hormone receptor-positive breast cancer patients, the relationship between RS and the risk of locoregional recurrence (LRR) remains unclear. The purpose of this study was to determine if RS is associated with LRR in breast cancer patients and whether this relationship varies based on the type of local treatment [mastectomy or breast-conserving therapy (BCT)].
  
  
  METHODS
  163 consecutive estrogen receptor-positive breast cancer patients at our institution had an RS generated from the primary breast tumor between August 2006 and October 2009. Patients were treated with lumpectomy and radiation (BCT) (n = 110) or mastectomy alone (n = 53). Patients were stratified using a pre-determined RS of 25 and then grouped according to local therapy type.
  
  
  RESULTS
  Median follow-up was 68.2 months. Patients who developed an LRR had stage I or IIA disease, >2 mm surgical margins, and received chemotherapy as directed by RS. While an RS > 25 did not predict for a higher rate of LRR, an RS > 24 was associated with LRR in our subjects. Among mastectomy patients, the 5-year LRR rate was 27.3 % in patients with an RS > 24 versus 10.7 % (p = 0.04) in those whose RS was ≤ 24. RS was not associated with LRR in patients who received BCT.
  
  
  CONCLUSIONS
  Breast cancer patients treated with mastectomy for tumors that have an RS > 24 are at high risk of LRR and may benefit from post-mastectomy radiation.
authors.affiliation: Department of Radiation Oncology, Winship Cancer Institute, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Naresh K
authors.initials: NK
authors.lastname: Jegadeesh
authors.forename: Sunjin
authors.initials: S
authors.lastname: Kim
authors.forename: Roshan S
authors.initials: RS
authors.lastname: Prabhu
authors.forename: Gabriela M
authors.initials: GM
authors.lastname: Oprea
authors.forename: David S
authors.initials: DS
authors.lastname: Yu
authors.forename: Karen G
authors.initials: KG
authors.lastname: Godette
authors.forename: Amelia B
authors.initials: AB
authors.lastname: Zelnak
authors.forename: Donna
authors.initials: D
authors.lastname: Mister
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Switchenko
authors.forename: Mylin A
authors.initials: MA
authors.lastname: Torres
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008408:Mastectomy; D015412:Mastectomy, Segmental; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000378:metabolism; D009367:Neoplasm Staging; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone